prolec book

Installation, Operation and Maintenance ManualPower Transformers Division

GE PROLEC makes no representation or warranties express or implied, with respect to any information contained in this Manual of Installation, Operation and

Table of Contents Section 1 ............................................................................................................................................................................. 5

INTRODUCTION ................................................................................................................................................................... 5 Section 2 ............................................................................................................................................................................. 7

SAFETY.............................................................................................................................................................................. 7 2.1 Introduction ........................................................................................................................................................ 7 2.2 Basics ................................................................................................................................................................ 7

2.2.1 Personal Safety .......................................................................................................................................... 7 2.2.2 Stay Alert .................................................................................................................................................... 7 2.2.3 First Aid ...................................................................................................................................................... 7 2.2.4 Personal Protection .................................................................................................................................... 7 2.2.5 Protection for Mechanical Hazards ............................................................................................................ 7 2.2.6 Protection for Electrical Hazards ................................................................................................................ 7

2.3 Safety Notations and Alerts ............................................................................................................................... 8 2.3.1 Danger........................................................................................................................................................ 8 2.3.2 Warning ...................................................................................................................................................... 8 2.3.3 Caution ....................................................................................................................................................... 8

2.4 Transformer Fire Safety..................................................................................................................................... 8 2.5 Safety Recommendations when the Transformer is under Pressure or Vacuum ............................................. 8 2.6 Grounding Precautions...................................................................................................................................... 9 2.7 Internal Environment.......................................................................................................................................... 9 2.8 Transformer Oil Handling ................................................................................................................................ 10 2.9 Electrical Hazards............................................................................................................................................ 10 2.10 Mechanical Hazards..................................................................................................................................... 10 2.11 General Safety Rules and Procedures ........................................................................................................ 11

2.11.1 Cautions for climbing on the transformer. ................................................................................................ 11 2.11.2 Liquid level indication. .............................................................................................................................. 11 2.11.3 Cooling equipment. .................................................................................................................................. 11 2.11.4 Transformer electrical tests. ..................................................................................................................... 11 2.11.5 Condenser bushing. ................................................................................................................................. 11 2.11.6 Cleanliness. .............................................................................................................................................. 12

Section 3 ........................................................................................................................................................................... 13 TRANSFORMER SHIPMENT, RECEIPT, STORAGE, ASSEMBLY AND VACUUM FILLING ............................................................. 13 IMPORTANT NOTICE ................................................................................................................................................... 13 GENERAL FLOW CHART FOR TRANSFORMER RECEIPT, ASSEMBLY, OPERATION AND MAINTENANCE .................................... 14

Section 3A ........................................................................................................................................................................ 15 SHIPMENT, RECEIPT AND STORAGE OF POWER TRANSFORMERS........................................................................................ 15

3A.1 Introduction .................................................................................................................................................. 15 3A.2 Shipping Practices ....................................................................................................................................... 15

3A.2.1 Shipping Preparation ............................................................................................................................ 15 3A.2.2 Loading ................................................................................................................................................. 15 3A.2.3 Transportation Additional Notes ........................................................................................................... 16 3A.2.4 Accessory Packing ............................................................................................................................... 17 3A.2.5 Identification.......................................................................................................................................... 19 3A.2.6 Miscellaneous Information .................................................................................................................... 19

3A.3 Transformer Receipt .................................................................................................................................... 20 3A.3.1 Prior to Unloading ................................................................................................................................. 20 3A.3.2 Unloading.............................................................................................................................................. 23

Maintenance. Likewise, GE PROLEC shall not assume any responsibility or have any liability resulting from the selection or use of this Manual, by any person. This information does not intend to cover all the details of the equipment nor does it try to provide the procedures for every contingency of installation, operation andmaintenance. Professional expertise is a requirement for every person with the task of handling a power transformer. If you require additional information on any problemor particular subject, please contact GE PROLEC Service Department. Phone: 1-800-437-7653. Fax: x 2011 Rev. 1 –Updated the entire document. December 8th, 2005

Copyright © 2005 All rights reserved, PROLEC GE

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3A.3.3 External Inspection ............................................................................................................................... 24 3A.4 Storage......................................................................................................................................................... 24

3A.4.1 Storage Preparation.............................................................................................................................. 24 3A.4.2 Storage Periods .................................................................................................................................... 24 3A.4.3 Temporary Storage with Nitrogen......................................................................................................... 25 3A.4.4 Temporary Storage with Oil .................................................................................................................. 25 3A.4.5 Accessory Storage................................................................................................................................ 25

Section 3B ........................................................................................................................................................................ 27 INSTALLATION ASSEMBLY.................................................................................................................................................. 27

3B.1 Transformer Assembly Notes ...................................................................................................................... 27 3B.2 Internal inspection........................................................................................................................................ 27

3B.2.1 Oxygen Content .................................................................................................................................... 27 3B.2.2 Precautions. .......................................................................................................................................... 28 3B.2.3 Atmospheric Conditions........................................................................................................................ 28 3B.2.4 Internal Inspection Checklist................................................................................................................. 28 3B.2.5 Re-sealing............................................................................................................................................. 28

3B.3 Mounting Accessories and Parts ................................................................................................................. 28 3B.4 Cooling System Installation.......................................................................................................................... 29

3B.4.1 Radiator Installation .............................................................................................................................. 29 3B.4.2 Heat Exchangers .................................................................................................................................. 30

3B.5 Conservator Tank......................................................................................................................................... 30 3B.6 Bushing Turrets............................................................................................................................................ 31 3B.7 Current Transformers Preliminary Test........................................................................................................ 31 3B.8 Bushing Installation...................................................................................................................................... 31

3B.8.1 Lifting .................................................................................................................................................... 31 3B.8.2 Draw-Lead Bushings Installation .......................................................................................................... 32 3B.8.3 Bottom Connected Bushings ................................................................................................................ 33 3B.8.4 Bushings with Reservoir Tank .............................................................................................................. 33

3B.9 Accessory Installation .................................................................................................................................. 34 3B.9.1 Pressure Relief Device ......................................................................................................................... 34 3B.9.2 Rapid/Sudden Pressure Rise Relay ..................................................................................................... 35 3B.9.3 Oil Gas Monitor ..................................................................................................................................... 35 3B.9.4 Winding and Oil Temperature Indicators .............................................................................................. 35 3B.9.5 Ground Resistor Assembly ................................................................................................................... 35 3B.9.6 Liquid Level Gage................................................................................................................................. 35 3B.9.7 Surge Arresters..................................................................................................................................... 36 3B.9.8 Surge Counters..................................................................................................................................... 36 3B.9.9 Ground Bus Bars and Cables ............................................................................................................... 36 3B.9.10 Silica Gel Canisters .............................................................................................................................. 36 3B.9.11 Vent Piping............................................................................................................................................ 36 3B.9.12 Wiring.................................................................................................................................................... 37

Section 3C ........................................................................................................................................................................ 38 OIL FILLING PROCESS UNDER VACUUM.............................................................................................................................. 38

3C.1 Equipment .................................................................................................................................................... 38 3C.1.1 Oil Processing Equipment .................................................................................................................... 38 3C.1.2 Vacuum Pump ...................................................................................................................................... 38 3C.1.3 Test Equipment..................................................................................................................................... 38

3C.2 Materials....................................................................................................................................................... 38 3C.3 Leak Test ..................................................................................................................................................... 38

3C.3.1 Flanges and Threaded Joints Verification. ........................................................................................... 39



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3C.3.2 Pressure Decay / Variation. .................................................................................................................. 39 3C.4 Moisture Content Verification....................................................................................................................... 39

VACUUM DRY-OUT AND OIL FILLING FLOWCHART................................................................................................................. 40 3C.5 Transformer Vacuum Process Preparation ................................................................................................. 41

3C.5.1 Grounding ............................................................................................................................................. 41 3C.5.2 Valve Positioning .................................................................................................................................. 41 3C.5.3 Bushing Connections............................................................................................................................ 43 3C.5.4 Gauges ................................................................................................................................................. 43 3C.5.5 Oil Testing before Filling Process. ........................................................................................................ 43

3C.6 Vacuum Dry-Out Process ............................................................................................................................ 44 3C.7 Vacuum Filling Process for Transformers without Conservator .................................................................. 45 3C.8 Vacuum Filling Process for Transformers with Conservator .......................................................................47 3C.9 Post Filling Operations................................................................................................................................. 50

Section 4 ........................................................................................................................................................................... 51 PRE-START UP INSPECTIONS ............................................................................................................................................ 51

4.1 Paint Application .............................................................................................................................................. 51 4.2 Electrical Tests ................................................................................................................................................ 52

4.2.1 Oil Dielectric Properties............................................................................................................................ 52 4.2.2 Insulation Resistance ............................................................................................................................... 52 4.2.3 Insulation Power Factor............................................................................................................................ 52 4.2.4 Transformer Turns Ratio (TTR)................................................................................................................ 53 4.2.5 Core Insulation Resistance to Ground. .................................................................................................... 53 4.2.6 Bushing Power Factor. ............................................................................................................................. 53 4.2.7 Excitation Current. .................................................................................................................................... 53 4.2.8 Current Transformer Final Tests. ............................................................................................................. 53 4.2.9 Winding Resistance Test (Ohmic Resistance)......................................................................................... 54 4.2.10 Control Circuit Tests. ................................................................................................................................ 54 4.2.11 Alarm Test. ............................................................................................................................................... 54

4.3 Final Inspection................................................................................................................................................ 54 4.3.1 Leak Verification. ...................................................................................................................................... 54 4.3.2 Oil Level Gage.......................................................................................................................................... 54 4.3.3 Fans and Pumps. ..................................................................................................................................... 54 4.3.4 Valves....................................................................................................................................................... 55 4.3.5 Temporary Grounds. ................................................................................................................................ 55 4.3.6 Final Ground Connections........................................................................................................................ 55 4.3.7 Surge Arresters. ....................................................................................................................................... 55 4.3.8 De-energized Tap Changer...................................................................................................................... 55 4.3.9 Load Tap Changer. .................................................................................................................................. 55 4.3.10 Current Transformer Verification. ............................................................................................................. 55 4.3.11 Control Cabinets....................................................................................................................................... 56 4.3.12 Materials and Tools. ................................................................................................................................. 56 4.3.13 Main Tank Silica Gel Canister. ................................................................................................................. 56

Section 5 ........................................................................................................................................................................... 57 TRANSFORMER OPERATION AND MAINTENANCE GUIDE ...................................................................................................... 57

Operation.................................................................................................................................................................... 57 5.1 Service Conditions........................................................................................................................................... 57

5.1.1 Altitude...................................................................................................................................................... 57 5.1.2 Ambient Temperature............................................................................................................................... 57

5.2 Voltage Variation Conditions ........................................................................................................................... 57 5.3 Variation of the Auxiliary Voltage..................................................................................................................... 57



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5.4 Overload Conditions ........................................................................................................................................ 58 5.5 Self Cooled Transformer (ONAN).................................................................................................................... 58 5.6 Transformer with Forced Cooling System (ONAF or OFAF)........................................................................... 58 Maintenance ............................................................................................................................................................... 59 5.7 Safety Procedures during Internal Inspection and Maintenance or Repairs. .................................................. 59

Section 6 ........................................................................................................................................................................... 60 STATEMENT OF ENVIRONMENTAL ACCESSORY TRANSFORMER COMPONENTS ..................................................................... 60

Section 7 ........................................................................................................................................................................... 61 CHECKLISTS..................................................................................................................................................................... 61

Main Data ................................................................................................................................................................... 61 Receiving Inspection Check List ................................................................................................................................ 62 Storage Inspection Check List.................................................................................................................................... 64 Internal Inspection Check List .................................................................................................................................... 67 Assembly Inspection Check List................................................................................................................................. 70 Vacuum Process Log ................................................................................................................................................. 74 Vacuum Drop Test Recording Chart .......................................................................................................................... 74 Pre-Startup Inspection Check List.............................................................................................................................. 75

MAINTENANCE INSPECTION CHECK LISTS .......................................................................................................................... 77 General Inspection Recording Form .......................................................................................................................... 77 Oil Tests Recording Form........................................................................................................................................... 79 Physical and Chemical Properties.............................................................................................................................. 79 Dissolved Gas Analysis Results................................................................................................................................. 80 Maintenance External Inspection Recording Form .................................................................................................... 81

ROUTINE ELECTRICAL TESTS CHECKLIST........................................................................................................................... 82 Winding Resistance Recording Form......................................................................................................................... 83 Insulation Power Factor Recording Form................................................................................................................... 84 Bushings Power Factor Recording Form ................................................................................................................... 85 Excitation Current Test Recording Form.................................................................................................................... 86 Insulation Resistance Recording Form ...................................................................................................................... 87 Transformer Protective Devices Test Recording Form .............................................................................................. 88

Appendix........................................................................................................................................................................... 89 PAINT KIT......................................................................................................................................................................... 89 DEW POINT ANALYSIS & GRAPHICS................................................................................................................................... 90 INSULATION DRY-OUT PROCESS ....................................................................................................................................... 95 WINDING RESISTANCE AND INSULATION POWER FACTOR CORRECTION TABLES .................................................................. 97

Winding Power Factor Correction Table .................................................................................................................... 97 Insulation Resistance Correction Table...................................................................................................................... 97 Insulation Resistance Correction Worksheet ............................................................................................................. 98

DAMAGE CLAIM FORM CARRIER NOTICE............................................................................................................................ 99 QUICK DECISION CONTINUOUS CAPACITY CHART ............................................................................................................100 OIL PROPERTIES GUIDELINE TABLE.................................................................................................................................101 RECOMMENDED TESTS AND REFERENCE VALUES FOR TRANSFORMER MINERAL OIL (*).....................................................101 SUGGESTED MAXIMUM WATER CONTENTS IN MG/KG (OR PPM) AND PERCENT SATURATION (*) ................................................101 GENERAL MAXIMUM TORQUE VALUES TABLE...................................................................................................................102 SPECIFIC COMPONENT TORQUE VALUE TABLE.................................................................................................................103 OIL FILLED BUSHING RESERVOIR ....................................................................................................................................104 CURRENT TRANSFORMERS .............................................................................................................................................105 QUICK REFERENCE OF USEFUL STANDARDS AND GUIDES ................................................................................................110 TROUBLESHOOTING TABLE .............................................................................................................................................111



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Section 1 Introduction

GE PROLEC transformers are professionally designed and manufactured according to the highest quality industry standards to provide efficient, reliable and long lasting service. In order to assure safe satisfactory operation and trouble free service of your transformer, only qualified and experienced personnel should be allowed to perform any activities related to the transformer as described in this manual. This manual relies upon GE PROLEC engineering standard practices for design and manufacturing. Moreover, instructions and procedures contained herein are enhanced with information from technical sources such as ANSI/IEEE standards and have been complemented with recommendations derived from customer specifications, supplier’s information and GE-PROLEC experience. This manual does not intend to cover all possible contingencies during installation, operation or maintenance, and all details or variations of this equipment. For further information, contact the GE PROLEC service department.

GE PROLEC Customer Service Department: Boulevard Carlos Salinas de Gortari Km. 9.25

Apodaca, N.L., 66600, México USA and Canada: 1-800-437-7653

Phone: 011-5281-8030-2360 Fax: 011-5281-8030-2011

www.prolecge.com



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http://www.prolecge.com/



In this manual, checklists for receiving, storage, offloading, assembly, operation and maintenance have been provided

to assure the proper execution of the entire transformer related activities. In order to maintain the agreed upon warranty,

these checklists must be filled out accordingly and sent to the GE PROLEC customer service department.

The above-mentioned checklists are provided in the Section 7 of this manual.

The following flow chart illustrates a common cycle once the transformer is shipped from the factory:

Receiving

Operations to confirm a proper arrival at its finaldestination

Assembly Activities and operations necessary to assembleand oil fill the transformer.

Operation Understood as the time when the transformer isplaced in service.

Maintenance Predictive, preventive, and corrective activitiesperformed to assure a safe and reliable operation.

Offloading Hauling maneuvers required for placing thetransformer in a storage location or final operationposition.

Storage When the site conditionsnecessitate storage.

Pre-start up testing The required activities and tests necessary toassure that the transformer is in proper condition forenergizing.



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Section 2 Safety

2.1 Introduction

Power transformer installation, operation, and maintenance shall follow strict safety procedures. A complete understanding and implementation of this Safety Section will minimize or eliminate possible dangerous situations and conditions. In addition, the following safety regulation standards must be applied:

• OSHA regulations • State and local safety laws • Your corporate safety working standards • National Electrical Safety Code

2.2 Basics

2.2.1 Personal Safety

Personal safety is first. Stop any activities, if unsafe working conditions exist. All team members must follow safety practices in order to avoid unsafe actions.

2.2.2 Stay Alert

Certain conditions can lead to emergencies. A risk assessment plan should be available prior to the start of any job.

2.2.3 First Aid

All personnel involved in the transformer activities should be aware of First Aid practices and CPR (cardiopulmonary resuscitation). Contact information for professional emergencies services should be available.

2.2.4 Personal Protection

Personal protective clothing and equipment must be worn as the work task dictates. Wear long sleeve cotton shirts, safety shoes, rubber boots, leather gloves, safety glasses, hard hats, safety harnesses and hearing protection as required. Avoid loose fitting clothing, jewelry (rings, watches and chains), tennis shoes, shorts, short sleeve shirts and radio earphones.

2.2.5 Protection for Mechanical Hazards

Avoid working under blocked or raised equipment and never attempt to repair equipment under operation. Severe personal injury may occur.

2.2.6 Protection for Electrical Hazards

Avoid working on energized circuits. Use protective tag and lockout system. Utilize temporary grounds. Utilize wiring diagrams to identify power supply sources.



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2.3 Safety Notations and Alerts

2.3.1 Danger

Immediate hazards which will result in severe injury, death or property and catastrophic equipment damage.

2.3.2 Warning

Hazard or unsafe work practices which may result in severe injury, death or property and catastrophic equipment damage.

2.3.3 Caution

Hazard or unsafe work practices which may result in minor injuries or property and unnecessary equipment damage.

2.4 Transformer Fire Safety

• Do not allow smoking, welding, or exposed flames on top and/or inside of the transformer or near any oil handling equipment.

• Do not pressurize a transformer with pure oxygen as an explosion may occur.

• Do not weld on a transformer unless it is absolutely necessary and previously approved by the GE

PROLEC Service Department. If any welding needs to be done, the unit must be completely filled with either oil or dry nitrogen.

• Firefighting equipment should always be available whenever working on the transformer.

2.5 Safety Recommendations when the Transformer is under Pressure or Vacuum

• If the transformer is pressurized or under vacuum do not attempt to open any manhole cover or remove any devices bolted to the transformer. Severe personal injury may occur.

• For dry air/nitrogen shipments, use the upper filling valve to release the pressure slowly. For oil filled

shipments, release the pressure through the gas cabinet sampling valve or throughout the vacuum pressure bleeder vent if applicable. Failure to follow these instructions may cause severe personal injury, death or equipment damage.

• Pressure gauge reading could be inaccurate and zero reading should be confirmed by releasing pressure

from the upper filling valve or the vacuum pressure bleeder if applicable.

• Do not attempt to lift or jack up a transformer with more than 3 psig internal pressure. The excessive pressure could cause base plate problems.

• Do not attempt to move, hit or work on the transformer if the unit is under vacuum.



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• Do not start the vacuum process on the main tank if:

The load tap changer compartment is not pressure equalized with the main tank using the appropriate interconnection tubing. Once the vacuum filling process is complete, this tubing must be removed and the valves plugged. This is to prevent connection board breakdown or leak problems.

The conservator tank bladder is pressure equalized with the main tank by means of opening the proper

valve between the bladder and conservator. This valve should be closed once the vacuum filling process has been completed. This is to prevent bladder damage.

2.6 Grounding Precautions

• The transformer tank must be grounded during and after installation

• All bushings must be grounded during the transformer installation and vacuum filling process except when tests are performed. Before energizing assure the proper removal of the temporary grounds.

• Test equipment must be properly grounded according to its user’s manual.

• Current transformer leads without connection to auxiliary circuits must be shorted and grounded.

• Oil processing equipment must be grounded.

• Maintain all grounds on transformer line terminals for a minimum of 6 hours after oil filling or recirculation.

Polarization of insulating materials produces a voltage that sometimes takes days to completely disappear. 2.7 Internal Environment

Only authorized and qualified personnel may go inside the transformer to perform internal activities

• Transformers are usually shipped with high quality dry air with less than 0.05% impurities and dew point -50°C or lower.

• Before going inside any transformer, verify that the internal environment contains a minimum of 19.5%

oxygen and maximum of 50 ppm CO for an exposure period of up to 8 hours. For further information, refer the OSHA regulation.

• Internal components, insulation and oil can absorb oxygen thereby reducing the overall oxygen content.

Going inside the transformer with less than 19.5% oxygen content will cause immediate faint, which would soon lead to asphyxiation and death hazard.

• Continuously monitor the oxygen and CO content inside the transformer (top and bottom).

• Once the transformer is opened, maintain the required level of oxygen by means of a dry air source. Airflow

must be maintained at all times.

• When any internal activities are performed inside the transformer, always post a fully trained safety supervisor near the open manhole. He must have at all time visual contact or other type of communication with the personnel inside the transformer.



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2.8 Transformer Oil Handling

• Transformer oil shall not be spilled on the ground.

• An oil spill container kit should be available at all times while working in the transformer.

• Prolonged contact with transformer oil may cause skin rash and/or eye irritation.

• Do not open a transformer valve without first checking if the valve is connected to an oil handling equipment.

• Never remove a valve plug unless the valve is closed and a catch pan is below the valve plug.

2.9 Electrical Hazards

• Do not perform any related work on the control cabinet or any electric circuit unless all power supply sources have been identified and de-energized. Confirm the absence of voltage with an approved testing device.

• Never attempt to open a closed current transformer energized circuit, as this will cause an electrical shock.

• Do not work in any electrical circuit unless no back feed is present, the power source is removed and a lock

out and tag out (LOTO) procedure is in effect.

• Do not apply electrical power to any terminal or circuit when the tank is under vacuum, as an internal discharge might occur.

• Respect appropriate electrical clearances while bushing or winding tests are being performed. High turn

ratios will transform low potential sources into dangerously high potential sources.

• Condenser type bushings are capable of storing an electrical charge. Do not touch these bushings; unless the bushing cap has been grounded for at least 5 minutes.

2.10 Mechanical Hazards

• Extreme caution must be taken while working on top of a transformer. Spilled oil and water will make the cover very slippery.

• Always install a safety rope barrier around the perimeter of the transformer cover, or supply a fall restraint

(full body safety harness) while working on top of the transformer.

• Never lift or jack up a transformer unless the appropriate lifting lugs or jacking pads are used. Certified personnel and listed equipment should be considered. Never jack from the bottom tank floor or bottom or side braces.



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2.11 General Safety Rules and Procedures

The following is a list of some safety and cleanliness precautions that must be followed by anyone involved in moving, installing, operating or maintaining the transformer.

2.11.1 Cautions for climbing on the transformer.

In order to prevent damage to the transformer or injuries, none of the components (pipes, valves, radiators) shall be used for climbing or attaching safety lines. Since the surface might be slippery, caution must be taken while working on top of the transformer.

Never climb onto the transformer while it is energized as this could result in injury or even death due to electrical discharges.

Do not attempt to install, operate or perform any maintenance activity on this transformer without the proper knowledge and experience.

Safety information contained in this manual from section 2.1 through 2.11 must be followed during installation and processing of the transformer. Read the entire instruction book carefully before attempting to handle, install or energize the transformer. Failure to follow these precautions will result in equipment

damage, severe personal injury or death.

2.11.2 Liquid level indication.

Low level of oil could cause an electrical internal failure. Do not drain the transformer while energized. Oil samples may be taken from the bottom drain valve when the transformer is energized. When the transformer is in operation, the radiator valves and connection valves to the conservator tank must be fully opened.

2.11.3 Cooling equipment.

Prior to energizing, the transformer’s cooling system must be correctly installed and operational. Radiator and proper conservator valves must be opened. Improper operation will cause alarms and trip signals. Cooling fans and pumps must be operable.

2.11.4 Transformer electrical tests.

Do not touch any energized parts while tests are in progress. Dangerous voltages will exist.

2.11.5 Condenser bushing.

Caution should be taken while handling this type of bushing, as they are capable of storing electric charge after energizing transformer windings. If any job is required on the bushing, it must be grounded before touching the top terminal. For further information, refer to the manufacturer’s manual.



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2.11.6 Cleanliness.

Before going inside the transformer, wearing of clean protective coveralls and shoe covers or rubber is necessary. Avoid entering with coins, pens, jewelry, foreign materials or any other metallic items.

All items taken into the transformer should be inventoried; tied off with string or cotton tape and accounted for when work is complete (a tool checklist is included in the Appendix of this manual to aid the personnel in performing this task).



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Section 3 Transformer Shipment, Receipt, Storage, Assembly and Vacuum Filling

IMPORTANT NOTICE

In order to preserve the agreed warranty on your transformer, the following checklists, included in the Section 7, must be completed, archived by the customer and provided to GE PROLEC for future warranty purposes.

• Receiving Inspection • Storage Inspection (if applicable) • Internal Inspection • Assembly Inspection • Pre-Start Up Inspection • Every Six Months and Annually Maintenance Inspection

GE PROLEC Power Transformers Service Department US and Canada: 1-800-437-7653 / Option 5 / Fax extension: 2011 Outside US: + 52-81-8030-2011



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General Flow Chart for Transformer Receipt, Assembly, Operation and Maintenance

Transformer receipt

To be installed

immediately Storage

Storage checklist

Receipt checklist

Process Documentation

AssemblyAssemblychecklist

High Moisture

Insulation dryout process

Vacuum fillingprocess

No

Yes

Yes

No

Pre start-upactivities

Pre start-upchecklist

Transformer operation &maintenance

Operation &maintenance

checklist



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Section 3A Shipment, Receipt and Storage of Power Transformers

3A.1 Introduction

These instructions provide information related to shipping, receiving, handling and storage of your power transformer. Compliance with these instructions will ensure satisfactory operation and quality and will maintain the transformer’s warranty.

Read this entire section carefully before attempting to move, handle or store the transformer. Failure to follow these instructions could result in severe personal injury, death, equipment or property damage.

These instructions do not intend to cover all possible contingencies, which may occur during shipping, receiving handling and storing the transformer. If you require further information, please contact GE PROLEC representatives.

3A.2 Shipping Practices

Transformers are shipped from the factory either by truck (Lowboy truck), railcar, plane or ship.

3A.2.1 Shipping Preparation

Shipping preparations may vary only for the following conditions:

3A.2.1.1 Dry Gas or Oil Filled Transformers are shipped either oil filled or with high quality nitrogen or dry air with less than 0.05% impurities and - 58°F/- 50°C or lower dew point.

3A.2.1.2 Impact Recorders

Impact recorders are always installed on railcar shipments. On truck shipments, these are only installed per customer request.

3A.2.1.3 Bushings

Normally, transformers are shipped with the H.V. bushings removed to obtain proper transportation clearances. On dry gas shipped units, the H.V. bushing draw leads will be tied off internally to the internal cable support frame. On oil filled units, the H.V. draw leads will be tied off to the underside of the bushing flange blanking plate.

3A.2.2 Loading

3A.2.2.1 Factory Loading

Factory loading is assisted by the consideration of center of gravity symbols. The two most common symbols are the Center of Gravity for Shipment and the Center of Gravity for Operation.

3A.2.2.2 Center of Gravity

Center of Gravity Symbols are located on one side of the transformer and on one end. These should be used during unloading and for positioning the transformer on the pad. (See Figure 3.1 Center of Gravity Symbols)



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GE PROLEC makes no representation or warranties express or

Figure 3.1 Center of Gravity Symbols

3A.2.2.3 Mechanical Support The transformer will be loaded with the entire base contacting the truck or railcar’s bed. The platform must be covered with plywood sheets to maximize base contact.

Never load a transformer onto a transportslope and the transformer is

3A.2.2.4 Tie Down

Once the transformdown cables for railsecure the transform

3A.2.3 Transportation Additional Not

3A.2.3.1 Positive Pressure

Units are shipped wdew point of - 58°F/with an automatic o

3A.2.3.2 Impact Recorder

This device can recand magnitude of im

Maintenance. Likewise, GE PROLEC shall not assume any responinformation does not intend to cover all the details of the equipmmaintenance. Professional expertise is a requirement for every persor particular subject, please contact GE PROLEC Service DepartmenRev. 1 –Updated the entire document. December 8th, 2005 All ri

base covered with loose sheet metal. If the platform is on a slight unrestrained it may suddenly slide off the platform.

implied, with respect to any information contained in this Manual of Installation, Operation and

er is placed and centered on the platform, welded base blocks and tie shipment are used to secure it. For truck shipment, chains are used to er to the platform.

es

ith a positive pressure of 3 to 5 psig of extra dry air (dry air must have a - 50°C or lower). If requested by the customer the unit will be equipped perating gas control system.

ord a maximum of 160 days and is multi-directional, recording the time pacts.

sibility or have any liability resulting from the selection or use of this Manual, by any person. This ent nor does it try to provide the procedures for every contingency of installation, operation and

on with the task of handling a power transformer. If you require additional information on any problemt. Phone: 1-800-437-7653. Fax: x 2011

Copyright © 2005 ghts reserved, PROLEC GE

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3A.2.3.3 Transformer Inclination During transit, the transformer must be maintained upright with a maximum permitted inclination angle of 15 degrees with respect to the vertical.

3A.2.3.4 Accessories Removed for Shipment

The accessories that are removed for shipment (radiators, bushings, vent pipe, accessories, etc.) are indicated in the outline drawing and its assembly notes. All removed accessories are normally shipped in wooden crates or open wood pallets. They are identified on the transformer’s packing/shipping list. Temporary blanking plates are installed on the flange of every device, which was removed for shipment.

3A.2.3.5 Gaskets

All temporary blanking plates have shipping gaskets installed. A new set of gaskets is supplied for every item. In addition, some accessories are removed for shipment and their new gasket must be installed to prevent any leaks.

3A.2.3.6 Control Cabinet keys.

Control cabinet and impact recorder (if applicable) keys are attached to the nameplate’s mounting stud or inside the control panel door.

3A.2.4 Accessory Packing

3A.2.4.1 Shipping evidence

Critical steps in the transformer shipping preparation and quality verification are video taped and hard copy recorded.

3A.2.4.2 Bushings

Bushings are shipped in the original equipment manufacturer (OEM) packing crate. This packaging is improved with the use of additional restraining fasteners, foam padding, ¼ inch external plywood barriers and the top covered with UV resistant black plastic sheeting. For long-term storage (more than three months), these crates should be stored indoors. Refer to Figure 3.2 and 3.1.

Oil filled bushings normally are either shipped in vertical position or with the top elevated 15 degrees from the horizontal above the bottom end crating depending on size.

•

•

•

The bushing terminal cap, locking nut and draw lead pin are shipped either assembled to the bushing or conveniently attached to the bushing crate.

Bushings with reservoir tanks may be shipped either vertically or horizontally. If horizontal, the reservoir is properly filled and should no be tilted as it could allow air to enter the bushing. If vertical, the reservoirs must be assembled per section 3B.8.4 and the Appendix Section.



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GE PROLEC makes no representation or warranties express or

Figure 3.2 Large Bushing Packing Figure 3.3 Small Bushing Packing

3A.2.4.3 Radiators

Radiators are die-stamped with a match mark for proper transformer manifold location. Radiators are drained and sealed with gasketed blanking plates. They are stacked horizontally on wooden pallets and are separated with wooden slats. The horizontal shipping method allows the fans to be shipped mounted on the radiators.

The radiator plugs are sealed in the factooccur due to a bad

3A.2.4.4 Steel fastening and

These items are aubrace rods, separastamped and are ba

3A.2.4.5 Conservator Tank

Conservator tanks separation.

Maintenance. Likewise, GE PROLEC shall not assume any responinformation does not intend to cover all the details of the equipmmaintenance. Professional expertise is a requirement for every persor particular subject, please contact GE PROLEC Service DepartmenRev. 1 –Updated the entire document. December 8th, 2005 All ri

ry and leak tested. If these plugs are removed, an oil leak could seal and will not be covered by warranty.

implied, with respect to any information contained in this Manual of Installation, Operation and

mounting accessories xiliary parts as ladders and surge arrester supports, radiator diagonal tor angles, etc. All items have the transformer serial number die nded to an open pallet.

have wooden planks banded to their leg braces to provide ground

sibility or have any liability resulting from the selection or use of this Manual, by any person. This ent nor does it try to provide the procedures for every contingency of installation, operation and

on with the task of handling a power transformer. If you require additional information on any problemt. Phone: 1-800-437-7653. Fax: x 2011

Copyright © 2005 ghts reserved, PROLEC GE

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3A.2.4.6 Fragile Accessories Accessories such as pressure relief devices, sudden pressure rise relays, temperature gages, flow gages, bushing connectors and associated parts, touch up paint kit, installation gaskets and other small items are shipped separately. All wooden crates are covered with a durable, UV resistance, black, plastic sheeting. For long-term storage (more than three months), these crates should be stored indoors.

3A.2.5 Identification

All the accessories are identified with metallic nameplates or plastic identification tags. Inside and outside each crate there is a stapled packing list stapled.

ORDER

DESCRIPTION

NO. OF PIECES

DATE

Figure 3.4 Typical Identification Tag

3A.2.6 Miscellaneous Information

3A.2.6.1 Environmental

All the wooden crates used for shipping are recyclable and environmentally friendly. Stenciling paint used on crates is lead free.

3A.2.6.2 Impact Recorder Responsibilities

It is the responsibility of the customer or his representative to review the impact recorder chart (if applicable) before unloading the transformer. If external damage to the transformer is discovered or the transformer has received impacts or resonance; the following steps must be performed:

• Do not unload the transformer. • Do not open the transformer. • Notify the carrier and request immediate inspection. Fill out the claim form attached in

the Section 7. • Notify GE PROLEC Customer Service at 1-800-GE-PROLE (1-800-43-77653). • Take photographs or video recording of all visible damage indication.



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3A.3 Transformer Receipt

Read the entire instruction book carefully before attempting to handle, install, use or service the transformer. Failure to follow instructions could result in severe personal injury, death or property damage and may void

the warranty.

The following instructions are intended to help in receiving transformers to maintain their quality and reliability. A checklist to aid the customer in performing a receipt inspection is provided in the Appendix Section of this manual.

3A.3.1 Prior to Unloading

3A.3.1.1 Visual Inspection

A visual inspection of the transformer and its accessories must be performed:

• For rail shipment, verify the transformer base blocking. Look to see that there are no weld cracks, dents, base plate indentations or displacements.

• Tie down cables or chains must be tight. • Verify there is no visible damage such as dents, paint abrasions or broken support

braces on the side of the unit. • All accessories that are not inside crates (radiators, conservator, supports, etc.) must

be inspected. Damaged accessory crates must have their contents inspected. If any damage on the accessory crates is detected, please notify the GE-PROLEC customer service immediately 1-800-GE-PROLE (43-77653).

3A.3.1.2 Gas Pressure

• The internal gas pressure can be either positive or negative depending on the ambient

temperature at the receiving location. • If the transformer is received with negative gas pressure (partial vacuum), a dry air

(dew point of - 58°F/- 50°C or lower) source must be attached to the gas cabinet or the top-filling valve to break the negative pressure condition. Fill the unit to 3 psig.

• If the transformer arrives with zero pressure, you must pressurize it with a certified dry air source (dew point of - 58°F/- 50°C or lower) and increase the internal pressure to 5 psig.

• Having completed re-pressurization, let the transformer stand, un-disturbed, for 24 hours. This idle period is to: (1) allow any surface moisture on the insulation package to diffuse into the replenished dry air supply and (2) allow a drop leak check. After this 24 hours period perform an internal gas dew point measurement according to Section A.2 of the Appendix.



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• Do not lift or attempt to move a transformer with a gas pressure greater than 3 psig or with anegative (partial vacuum) gas pressure.

• Do not go inside any transformer without first confirming that the oxygen content of the transformerinterior 19.5 % or greater.

• Never attempt to fill a transformer with pure oxygen.

3A.3.1.3 Impact Recorder Removal and Tape Inspection

Definitions: G = Magnitude of gravity acceleration. Z - AXIS = Vertical acceleration (up and down motion). Y- AXIS = Longitudinal acceleration (front to back motion). X - AXIS = Transversal acceleration (side to side motion).

Open impact recorder and turn it off. Manually swing back and forth the recording stylus to indicate the moment of deactivation.

•

• •

•

•

Remove the impact recorder tape. Record on the tape the following information: • Time and date of deactivation. • Name of the person or representatives opening the impact recorder. • Name of the rail or truck carrier. If external or hidden damage is suspected, the railroad or carrier inspector has to be present and sign the appropriate claim form. If accelerations in any axis exceed the magnitude in Table 3A.1, an internal inspection must be performed to confirm the absence of any internal damage.

Transversal Longitudinal Vertical

G's G's G's Core and coil weight (pounds)

X Y Z 1 – 49,989 1.50 10.00 3.50

49,990 – 124,977 1.50 9.00 3.50 124,978 – 174,969 1.50 8.00 3.50 174,970 – 249,955 1.50 7.50 3.50 249,956 – 399,929 1.50 6.50 3.00 399,930 – 524,909 1.50 5.50 3.00 524,910 – 999,827 0.75 4.50 2.50

Table 3A.1 Allowable accelerations in each axis vs. core and coil weight

The chart should be read using the following instructions: - When the centerline of the stylus tracing is discernable the Table 3A.2 - Column 1 should be used to

determine the amount of G’s recorded. Count the number of spaces, or equivalent, from the centerline, one way, to the end of the arc that extends furthest from the centerline. Find the appropriate row on Column 1 and read the X, Y or Z acceleration.



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- When the centerline is not discernable, use the Table 3A.2 – Column 2. Count spaces from peak to peak (full swing of stylus trace) and lookup the appropriate row on Column 2 and read the X, Y or Z acceleration.

- Time is recorded on the topside of the chart. Three inches approximately equals one day. - The effects of resonant vibration of low magnitude G-force accelerations for extended periods of time

can also cause damage. Resonance can be induced depending on railcar speed, rail gap, the railcar wheel base length or bad road conditions.

- If the impact recorder graph indicates resonant induced vibration of low magnitude less than 1.0 G for periods greater than 8 hours, then complete the damage claim form in the Appendix Section.

- The recorder graph (paper recording tape) should be kept by the customer for any future reference.

Column 1 Read from center line (refer to Figure 3.5)

Column 2 Read full swing of arc (refer to Figure 3.5)

Axis X Y Z X Y Z Device maximum

recording limit 6 G 15 G 10 G 6 G 15 G 10 G

Inches Spaces 1/8 1 1.7 g 3.5 g 2.0 g 1.0 g 2.1 g 1.2 g 1/4 2 3.3 g 7.0 g 4.0 g 2.0 g 4.1 g 2.4 g 3/8 3 5.0 g 10.5 g 6.0 g 3.0 g 6.2 g 3.5 g 1/2 4 6.3 g 14.0 g 8.0 g 3.9 g 8.2 g 4.7 g 5/8 5 8.2 g 17.5 g 10.0 g 4.9 g 10.3 g 5.9 g 3/4 6 5.9 g 12.4 g 7.1 g 7/8 7 6.7 g 14.4 g 8.2 g 1 8 7.4 g 16.5 g 9.4 g

1-1/16 8.5 7.8 g 17.5 g 10.0 g

Table 3A.2 Typical instrument recording limits and reading of impact recording chart

In this case read the acceleration on Column 1

In this case read the acceleration on Column 2

Figure 3.5 Sample Impact Graph Figure 3.6 Impact Recorder Stylus

Z

Y

X

C L



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3A.3.1.4 Core Ground Test Use a 500 or 1000 VDC insulation resistance meter (MEGGER) to verify that the insulation between the main core and the frame is at least 20 MΩ @ 1 minute. The core ground bushing is located inside a small box on the cover or the sidewall of the tank. Check the outline drawing for reference on the exact location of this box on your particular transformer. When provided, also check all LTC reactor or series transformer cores.

3A.3.1.5 De-energized Tap Changer Inspection.

The DETC is locked in its nominal position with a bolt or a wire seal. If the handle is damage or the bolt or seal is missing, please fill out the Damage Claim Form Carrier Notice and inform GE PROLEC service department.

3A.3.2 Unloading

• The transformer must be maintained in an upright position with a maximum permitted inclination

angle of 15 degrees. • The transformer internal pressure must be reduced to 3 psig before lifting or jacking. The

centerlines of gravity must be considered (see Figure 3.1). • Never attempt to use less than a 3 inches thick rail or channel when sliding the transformer since

failure to do so will cause damage to the transformer base. • For crane lifting, use slings attached to the four available lifting points on the tank (see outline

drawing and Figure 3.7). The slings must be of adequate strength (see weights on transformer nameplate), should be of equal length and consider the form of the lifting lugs. The lifting lugs provided are designed to withstand the full weight of the transformer.

• The jacks should be placed under the four jack bosses as identified on the outline drawing. The jacks may be operated simultaneously or in pairs on one end taking care that the height difference on between both ends, is not more than two inches.

• After the unit has been set in its permanent position on the pad, verify that there are no gaps below any of the tie-pads on the base. Shim as necessary to assure even weight distribution.

Figure 3.7 Lifting procedure with slings Figure 3.8 Lifting procedure with jacks



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3A.3.3 External Inspection

A checklist to aid the customer in performing an external inspection is provided in the Section 7 of this manual.

3A.3.3.1 Control Cabinet

• Verify that the sealing labels between both cabinet doors have not been torn or removed.

• Check the light bulbs are installed. • Verify no damage occurred to the control conduit and fittings.

3A.3.3.2 LTC (Load Tap Changer) Cabinet

• Make sure LTC hand crank is in place • Verify the absence of damage in the cabinet.

3A.3.3.3 De-energized Tap Changer shaft inspection

The DETC is locked in its nominal position with a bolt or a wire seal. Remove the bolt or seal and operate the handle through every position. It should move smoothly and offer slight resistance indicating that it is operating.

3A.3.3.4 Radiator Valves • Make sure the blanking plates are in place. • Make sure there are no oil leaks from butterfly valve packing nut or from blanking plate

covers. • Verify radiator valves are closed and secured with bolt in place.

3A.4 Storage

A checklist to ensure proper storage of the unit is provided in the Appendix Section of this Manual.

3A.4.1 Storage Preparation

If after receiving the transformer, it is decided to continue with the storage period, all inspections and tests described in this section must be completed.

Transformer ground pad must be solidly connected to ground during the storage period.

3A.4.2 Storage Periods

The storage period starts the day the transformer is shipped by GE PROLEC and it ends the day the transformer is ready to be energized. It is recommended to fully assemble the transformer on the site where it is going to be located, even though the unit may be stored for a period of several months before it is energized.

During the storage period, the transformer should contain the following: dry nitrogen, dry air or transformer oil with a dry nitrogen gas blanket.



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Storage Period Recommendation

Up to 90 days Store the transformer filled with dry air or nitrogen (dew point of - 58°F/- 50°C or lower).

Between 90 and 180 days If the transformer has been filled with dry air, it should be vacuum removed and replaced with nitrogen (refer to 3A.4.3).

More than 180 days The transformer must be vacuum filled with oil (refer to 3A.4.4).

3A.4.3 Temporary Storage with Nitrogen

If the transformer cannot be installed immediately upon arrival and oil filling is impractical, it is possible to store the transformer under a positive dry nitrogen (dew point of - 58°F/- 50°C or lower) pressure for up to 6 months from the date of shipment after vacuum removal of dry air.

A positive pressure must be maintained at all times, the recommended internal pressure being 3 psig.

Transformer gas temperature and pressure and bottle pressure should be recorded every day for the first two weeks. These readings should be preferably taken at approximately the same time every day. After two weeks of daily logging, the pressure readings may be reduced to once a week. The nitrogen bottle pressure must never be allowed to drop below 200 psig.

3A.4.4 Temporary Storage with Oil

If the transformer will not be completely assembled and, storage beyond 6 months is anticipated, the transformer must be vacuum oil filled and a nitrogen blanket space must be maintained. The procedure for this purpose is to pull vacuum until a 1000 µHg is reached and then oil fill the transformer until the core & coil is covered. (Contact the GE PROLEC customer service department for the minimum oil level & gas space required).

At the end of the storage period, the record of the pressure readings must be reviewed to confirm that positive pressure was always maintained during the storage period. In addition, an oil sample should be drawn from the bottom-sampling valve of the transformer for oil screen analysis to insure moisture has not entered the transformer. If all tests are satisfactory, assemble the transformer using the installation section of this manual.

3A.4.5 Accessory Storage

In case the accessories are not mounted immediately after the transformer is received, they must be protected against damage or loss during their storage.

The transformer must be tagged indicating that it has been filled with nitrogen.

To avoid internal condensation inside the transformer’s control cabinet, the respective space heaters must be energized and operating during its entire storage period.

Accessories and parts must have indoor storage. If indoor storage is not possible, a weatherproof tarpaulin must be used to cover accessories wooden boxes.



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Store all the accessories on their own shipping pallets/crates and blocked up off the floor. Do not stack pallets or crates.

The bushings must be stored in their shipping crate. If a bushing is not stored in its shipping crate, precautions should be taken to provide adequate oil coverage by positioning the upper end above the lower end. An angle of seven degrees or higher above the horizontal must be maintained.

If for any reason the bushings were not stored according to the recommendation mentioned above, they must be placed in a vertical position for 48 hours prior to testing or energization.

Before starting the assembly process, a careful inspection and cleaning of all the accessories should be performed as necessary.



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Section 3B Installation Assembly

3B.1 Transformer Assembly Notes

A checklist to aid the customer in performing an internal inspection is provided in the Section 7 of this manual. The internal environment of the transformer must be purged with dry air before and during internal work. Dry air must have a dew point of - 58°F/- 50°C or lower.

The items removed and shipped separately are listed on the outline drawing, such as bushings, cooling equipment, forced oil pumps, arresters and arrester mounting brackets, sudden pressure relays, etc. Refer to the outline drawing for the accessories mounting location.

All field assembled pipefitting joints must be sealed with gas (yellow) Teflon™ tape.

3B.2 Internal inspection

3B.2.1 Oxygen Content

Do not open any covers or fittings unless zero gage pressure exists inside the unit. Failure to relief the pressure may cause equipment damage and personal injury or death.

• Be certain the internal pressure in the transformer is at zero before opening the manhole. • Do post a fire watch at the manhole. • Do not open the transformer when raining

Do not enter any transformer until the gas in the tank is replaced by dry air. Oxygen content inside the transformer must be at least 19.5% before entering the transformer. Dry air shipment does not imply that the oxygen content test may be safely omitted. The oxygen content must always be checked. Oxygen content

less than 19.5% may cause drowsiness and/or injury and death.

If the oxygen content is too low, it can be corrected by pulling vacuum and re-pressurizing with dry air with a dew point of –58°F/ 50°C or lower or by purging through a sampler valve. The air must be high purity.



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3B.2.2 Precautions.

Before entering, personnel must: • Remove all loose objects from clothing or body (coins, watches, chains). • Wear clean rubber boots and white Tyvek™ coveralls or similar. • Attach safety ties to flashlights and tools. • Purge all air hoses with dry air to remove all moisture and dirt prior to use. • Use a pressure regulator to reduce the pressure of the incoming air. • Air hoses may be taken into the transformer if they are clean, dry and made of oil proof material. • The dry airflow rate should be adjusted to maintain a continuous airflow through the tank openings. • The work sequence must be planned in such manner that when large parts (i.e. bushings, turrets)

are being installed, only one flanged opening, other than the manhole, will be opened at any time.

3B.2.3 Atmospheric Conditions

The transformer should not be open without precautions to minimize the moisture entrance. The number of openings and the exposure time should be kept to a minimum especially if the relative ambient humidity exceeds 60%.

3B.2.4 Internal Inspection Checklist

A checklist to aid the customer in performing an internal inspection is provided in the Section 7 of this manual. The internal inspection should include at least, the following inspections:

Inspect and remove any internal shipping braces. •

• Absence of any abnormal looseness or movement caused by shipping. Hardware securing the unit in the tank and the winding jacking screws must be tight.

3B.2.5 Re-sealing

If the assembly would not be performed immediately after internal inspection, re-seal the unit and re-pressurize the tank to 3 psig following any of the processes listed below. • One is to fill the unit with dry nitrogen or air with dew point of –58°F/ 50°C or lower, to 2 psi, wait for

15 minutes and release the pressure; this process must be repeated one more time before the final pressurization.

• The other method is to pull vacuum (2 Torr/2000 µHg) for 1 hour, break the vacuum and pressurize the transformer to 3 psi with dry air or nitrogen with dew point of –58°F/ 50°C or lower.

If any damage or problems are found, notify the GE PROLEC Product Service Department at 1-800-GE-PROLE (43-77653).

As a reference, a 50” tall dry air or nitrogen bottle filled to 2000 psi will expand approximately to a volume of 4700 gal at 3 psi in the transformer tank; similarly a 60” tall bottle will expand to 8600 gal at 3 psi. This rule of thumb can be used to calculate the number of bottles needed to pressurize a transformer by looking at the nameplate and using the gallons of oil as the volume to be filled.

3B.3 Mounting Accessories and Parts

The assembly sequence of the accessories is not the same for all type of transformers and must be adjusted in accordance to the type of construction and the environmental conditions of each site.



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3B.4 Cooling System Installation

The transformer cooling system will have either heat exchangers or radiators; correct installation is imperative for proper transformer operation.

3B.4.1 Radiator Installation

All radiators have die stamped marks on each flanged connection; these marks should match their respective counterpart (i.e. tank flange “X” to radiator flange “X”). In addition, the radiators are shipped with fans installed. The following steps will lead to successful installation.

Step 1 Verify the radiator valves are in closed position. Remove blanking plates from the first radiator tank valves and replace shipping gaskets with the new gaskets provided.

Step 2 The flanges should be cleaned and inspected to confirm the absence of any imperfections. Install the new gaskets.

Step 3 Lift the first radiator from the stack (horizontally using all four lifting eyes) and set it on blocking wood to avoid damage and chips to the paint.

Step 4 Attach lifting-cables/slings to the top header, raising and rotating the radiator to vertical position

Step 5 Lift and position the radiator, aligning the flanges. Install all flange bolts making final vertical adjustment. Verify gasket installation before tightening in a cross pattern. Refer to torque table in the Appendix Section.

Step 6 Install adjacent support rod to tank mounting lug. Rods have fasteners included.

Step 7 Repeat process for all radiators.

Step 8 Once all the radiators and rods of one bank are installed, insert every rod on the lower cross-angle support and attach it to the lower lifting lugs of the radiator. See next example figure.

Support rod

Cross-angle

Support rod

Cross-angle

Bolt

Nut & lock-washer

Flat square washer

Example of radiator support rods installation.

Step 9 Lead radiator support rod while raising brace connecting to one end of the radiator-lifting eye. Assemble remaining hardware.

Step 10 Install upper separator bracket after radiator flange bolts are tight.



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Step 11 When radiator drain valves are supplied and not installed (if applicable); remove the bottom drain plugs, place a dripping pan under the plug to catch any residual oil that may be in the radiator. Replace the plugs with the supplied nipples and valves using gas (yellow) Teflon™ tape on the threads.

Step 12 If unit is oil filled, remove the upper vent/fill plug, clean the thread of the radiator coupling and male plug, apply four to five wraps of gas (yellow) Teflon™ tape. Install plug without tightening it, this will permit venting the radiator. Slowly open the bottom radiator valve and allow the oil to rise while purging the air, when the oil reaches the upper header, close the bottom valve and torque the plug as per torque table (see the Appendix Section). Both radiator valves may now be opened and locked to its final position.

Step 13 If unit is shipped with dry air, delay opening the radiator valves until ready to perform leak test and vacuum oil fill. This reduces the volume that must be pressurized during assembly, and keeps the ambient air trapped inside the radiators.

• Do not remove the radiator drain plugs unless you are replacing them with valves. • Always replace shipping gaskets with operational gaskets. • For proper transformer cooling all radiator valves must be fully open with safety bolts installed on

butterfly valves.

3B.4.2 Heat Exchangers

Heat exchangers are removable cooling units comprised of valves, a pump, piping, fans, o-ring packing and a heat transfer device. All die stamped marks on each flanged connection should match its respective pair (i.e. tank flange “X” to cooler flange “X”). The following steps will lead to successful installation.

Step 1 Remove tank valve blanking plates, along with shipping gaskets. CAUTION: Make sure valves are closed.

Step 2 Install the new gaskets provided for that use.

Step 3 Install circulating pump and inlet valve.

Step 4 Install heat exchanger after removing blanking plates. Replace all shipping gaskets with new operational gaskets.

Step 5 Install flanged pipe extension from upper and bottom valves to the exchanger and apply proper torque as per tables included in the Appendix Section.

3B.5 Conservator Tank

The first step is to install the conservator supports (if applicable) on the main tank. Prior to installing the conservator tank, the interior must be inspected, assure the bladder is properly mounted, the level gage float arm is not bent and bladder not obstructing the float arm. Once the inspection is completed, replace the manhole-shipping gasket with a new gasket. Finally, install the conservator tank directly on to the supports.



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Vent piping should not be assembled until all other cover accessories have been installed. This will avoid damages and/or a possible tripping hazard.

Install the Buchholz relay assuring that the flow indication arrow point towards to the conservator tank.

Finally, complete the connection to the tank.

B.6 Bushing Turrets

done by removing each shipping cover one at a time, in order to minimize the exposure time to the environment.

oving the flange cover from the main tank and turret base, clean the gasket grooves and install the new

gasket.

.7 Current Transformers Preliminary Test

lation resistance and ratio test every CT to ssure no damage exists that could have been caused by shipping.

he replacement CT if applicable. GE PROLEC will not cover any activities related to the replacement of the CT’s.

B.8 Bushing Installation

3B.8.1 Lifting

the upper end above the lower end to avoid introducing any gas bubble into the bushing insulation.

Assure to remove the Buchholz shipping spacer protection for the alarm and trip test button.

3

If the transformer is provided with bushing turrets, the mounting of the bushing’s turrets must be

Upon rem

3B

Before installing the bushings, it is mandatory to perform an insua Please carefully perform these tests, as any CT problems detected once the unit has been assembled will not be considered as a warranty issue. After evaluating each case, GE PROLEC will only provide t

3

For lifting, the sling should be placed as shown in figures 3 - 9 and 3 - 10. During the lifting operation, the inclination of the bushing should be adjusted with a guide rope. The oil level indicator must be pointing out wards from the main tank. The lifting procedure should always be performed taking care of maintaining



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Figure 3 - 9 Method used to lift short bushings (usually less than 230 kV)

Figure 3 - 10 Method used to lift large bushings (usually 230 kV and up)

3B.8.2 Draw-Lead Bushings Installation

Step 1 Retrieve the draw lead from inside the transformer, check all threads are clean and with no damage. Transformers shipped with oil have their draw-leads fastened to the underside of the respective bushing flange blanking plate. Transformers shipped with dry air/nitrogen have their draw-leads fastened to the wooden cable support frame.

Step 2 Clean the bushing with dielectric solvent before installing.

Step 3 Install the new gaskets.

Step 4 Once the draw lead has been retrieved, tie a strong non-abrasive nor metallic cord to the lead introducing the other end of the cord up through the bushing from bottom to the draw lead cap.

Step 5 Simultaneously; lower the bushing into the transformer while extracting/pulling the draw lead up through the bushing. After the bushing has come to rest on the cover/turret, verify that there are no kinks in the cable below the bushing and that sufficient strike distance exists between the cable and surrounding tank wall, core clamps, etc.

Step 6 Once the threaded top and the retaining pinholes are aligned, install the retaining pin and contact nut (if applicable). When draw lead is secured, remove the draw lead cord (refer to Figure 3-11).

Step 7 Verify that the top terminal threads (internal and external) and cap gasket is not damaged. Clean with dielectric solvent and install the bushing cap (refer to Figure 3-12).

Step 8 Finally tighten and torque all the bolts a cross pattern according with the Appendix Section.



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Bushing flanges are made of metal casting. Do not exceed the following suggested torque values, as permanent damage will occur.

Figure 3 - 11 Draw Lead and Retaining Pin Figure 3 - 12 Final Connector Cap

Draw LeadCap

Gasket

RetainingPin

Draw Lead

3B.8.3 Bottom Connected Bushings

Step 1 Install the new gaskets.

Step 2 Install bushings, making sure that mating flanges are clean and with no damage.

Step 3 Install internal bushing connectors and assure that the bushing blade machined surface is in electrical contact with the flexible copper connection. Finally, tighten and torque all the bolts in a cross pattern according with the table in the Appendix Section.

Step 4 Tighten and torque the entire flange bolts in a cross pattern according with the Appendix Section.

3B.8.4 Bushings with Reservoir Tank

3B.8.4.1 Bushings shipped with the reservoir tank not installed.

Step 1 Lay the bushing horizontally with the reservoir-mounting hole facing up.

Step 2 Remove the plug from the flange.

Step 3 Measure the bushing oil temperature using a thermocouple.

Step 4 Thread the supplied reservoir into the flange making sure the “O” ring is properly sealed.



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Step 5 Remove the plug and dipstick from the reservoir and add the supplied oil until the level measured by the dipstick reaches the proper level at the measured temperature, see the Appendix Section.

Step 6 Move the bushing slightly back and forth to force all air bubbles out of the bushing.

Step 7 Refill to proper level and repeat until all air is out of the bushing.

Step 8 Install the plug and dipstick making sure the “O” ring is properly seated.

Step 9 Install the new gaskets and mount the bushing. Make sure it stays horizontal and no air gets into the bushing.

Step 10 Tighten and torque the entire flange bolts in a cross pattern according Appendix

3B.8.4.2 Bushings shipped with the reservoir tank installed

Step 1 Lay the bushing horizontally with the reservoir facing up.

Step 2 Install the new gaskets and mount the bushing. Make sure it stays horizontal and no air gets into the bushing.

Step 3 Tighten and torque the entire flange bolts in a cross pattern according with the Appendix Section.

• Never remove upper sight glass fill plug when a bushing is hot. The oil inside the bushing is under

pressure, which might cause injuries to the personnel around it if suddenly released. • If bushing internal connections are scratched, clean with a scouring pad (i.e. Scotch-Brite) until a

smooth surface is obtained. • Always tighten flange bolts in a cross-sequential pattern. (Refer to Torque Table in Appendix A.). • Always install protective grounds on capacitive bushings during oil filling operations or oil re-circulation. • Leave grounds attached to bushings after any oil operation or test for a minimum of one (1) hour. • Make sure the reservoir tank is facing up.

3B.9 Accessory Installation

3B.9.1 Pressure Relief Device

Transformers could have one or more of these devices located on the main cover and on the Load Tap Changer. For detail on location, refer to the outline drawing. This device withstands vacuum and can be installed before vacuum oil filling. However, the opening flanges of these devices could be used for connecting vacuum hoses. To assemble the flag remove one of the cover screws and install the flag so it is centered over the operation indicator pin.

Never remove more than one screw from the PRD cover; this cover is under spring tension.



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3B.9.2 Rapid/Sudden Pressure Rise Relay

Install the relay after vacuum filling process. Once the device is installed the bleed valve should be opened long enough to allow one half pint of oil to flow out.

3B.9.3 Oil Gas Monitor

Special tools are provided in the accessory crate. The Oil Gas Monitor Instruction Book provides assembly instructions. After the oil filling process, open the valve and bleed the sensor as directed in the instruction book. It is mandatory to read the manufacturer Oil Gas Monitor manual for its installation and operation.

For transformers that have the rapid/sudden pressure relay shipped installed, make sure the valve is closed during the vacuum filling process.

Never attempt to touch the internal sensor membrane; this will nullify the warranty of the gas monitor. Never install the gas monitor sensor membrane before the vacuum process, damage to membrane will occur.

3B.9.4 Winding and Oil Temperature Indicators

The temperature indicators should be mounted on the support above or next to the control cabinet. The capillary tubes must be inserted into the appropriate thermo-well and the retaining nut tightened. Capillary tubes and thermo-wells are tagged for proper identification. The capillary cable must be routed through the support channel(s) and the excess cable should be coiled and secured with plastic ties. When the transformer is de-energized, all temperature gauges (liquid and winding) should indicate the exact same temperature plus minus the tolerance indicated in the drawings. If not, then at least one gauge is in error. If this happens, please contact GE PROLEC service department.

3B.9.5 Ground Resistor Assembly

The ground resistor may be mounted on the transformer cover or a separate support assembly. Position the resistor’s top bushing next to the transformer’s neutral bushing as shown on the outline drawing. The ground stud on the bottom of the ground resistor assembly must be connected to a transformer ground pad.

3B.9.6 Liquid Level Gage

The liquid level gage is made of three main components; the float, the non-magnetic mounting flange and the dial bezel & case assembly. The dial bezel & case assembly should be mounted on the flange using the provided screws. The liquid level gage may be mounted on the main tank, on the conservator tank or on the LTC tank.



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GE PROLEC makes no representation or warranties express or impl

3B.9.7 Surge Arresters

The surge or lightning arresters must be mounted on their supports so their discharge chutes point away from the transformer. If the arresters are stacked two or more high, the surge arrester’s nameplate will describe the correct stacking sequence. If supplied with matching serial numbers, verify that the numbers in each stack are the same.

3B.9.8 Surge Counters

If counters are supplied with the surge arresters, they should be mounted as shown on the outline drawing and assembled per the brochure. Note that insulators are supplied to provide isolation from the surge arrester support.

3B.9.9 Ground Bus Bars and Cables

The ground bus bars or cables are identified as to their location on either the high or low voltage side of the transformer. The sections, if shipped separate in the accessories crate, will be match marked to the tank wall as to their proper location.

3B.9.10 Silica Gel Canisters

Silica gel canisters are provided to avoid the entrance of moisture to the conservator bladder or the load tap changer. Conservator transformers and load tap changers equipped with these canisters are zero pressure vessels.

After assembly, fill the cup locatedlevel.

3B.9.11 Vent Piping

To prevent any damage, the vent transformer. Each pipe is identifiedeach piece of stainless steel pipe arTighten each compression fitting witgas (yellow) Teflon™ tape to thenecessary in the compression side o

The shipping plastic storage plugs must bwill cause a unit shut dow

Vent piping system shall not to be used to point, will cause damage to th

Maintenance. Likewise, GE PROLEC shall not assume any responsibilitinformation does not intend to cover all the details of the equipment nmaintenance. Professional expertise is a requirement for every person wior particular subject, please contact GE PROLEC Service Department. PhRev. 1 –Updated the entire document. December 8th, 2005

CAll rights

e removed to allow free breathing. Failure to remove these plugs n and/or cause leaks at various gasket locations

ied, with respect to any information contained in this Manual of Installation, Operation and

on the bottom of the canister with transformer oil to the indicated

piping system should be the last item to be installed on top of the as to its points of connection, (bushing, manhole, etc). Assemble ray from its designated cover high point to the manifold. h two wrenches to avoid twisting the pipe and causing a leak. Apply tapered side of all threaded fittings to avoid leaks, this is not f the fitting.

attach the safety harnesses. Using this tubing, as a safety hook upe tubing, leaks on fittings and may cause an accident.

y or have any liability resulting from the selection or use of this Manual, by any person. This or does it try to provide the procedures for every contingency of installation, operation and

th the task of handling a power transformer. If you require additional information on any problemone: 1-800-437-7653. Fax: x 2011 opyright © 2005 reserved, PROLEC GE

IOMM-ENG of 114



3B.9.12 Wiring

Verify that each device that was assembled on the transformer is properly connected to the control cabinet. Most devices are provided with convenience plugs. If plug connections have not been provided, secure the cable to the device and wire the terminal lugs to the connection blocks indicated on the connection diagram for external connections. It is necessary to make sure current transformers are grounded.

I M P O R T A N T

For further installation, operation and maintenance information on each accessory included in your transformer, please consult the following webpage: www.prolecge.com where you can download the OEM

catalogs.



IOMM-ENG of 114



Section 3C Oil Filling Process under Vacuum

After the transformer is completely assembled, proceed with the preparation for vacuum dry-out and oil filling. GE PROLEC transformer tanks and conservator tanks are designed to support full vacuum; however, there are components that do not withstand vacuum, such as LTC terminal board, Hydran sensors, rapid/sudden pressure relays and conservator bladders. Certain precautions must be taken to avoid any damage to these devices during the vacuum process. Detailed information is included in this section. Preparations for Vacuum Oil Filling 3C.1 Equipment

These are the minimum recommended equipment ratings for processing new transformers.

3C.1.1 Oil Processing Equipment

• Oil pump and hoses with a mechanical filter capable of 10 (preferably 5) µm retention at a flow rate at least 1200 gal/h.

• Oil heating equipment to suit climatic condition preferably capable of at least + 50°C oil output at 1200 gal/hr (1.3 L/s).

• Oil vacuum chamber with a final stage operating below 1 mmHg (130Pa) at a design flow of at lest 1200 gal/h (1.3 L/s), during the final oil filling process.

• Oil storage container. • The processing equipment above should be capable to reduce water content in the oil below 10

ppm and the dissolved gas content up to or below 0.5%.

3C.1.2 Vacuum Pump

• Mechanical vacuum pump capable to reach at least 0.05 mmHg (7Pa) with valve closed and at least 350-ft3/min of displacement, the use of a high-capacity mechanical booster vacuum pump should be considered.

3C.1.3 Test Equipment.

• A dew point meter capable of operating at low inlet pressure and having enough resolution to read

lower than –60°C dew point. • Oil dielectric test set (power factor and dielectric tester equipment) • Vacuum measuring instrumentation must be suitable to measure below 0.1mmHg. (100 microns).

3C.2 Materials

The only material needed is dry air or nitrogen with a dew point of - 58°F/- 50°C or lower. 3C.3 Leak Test

After the assembly process is completed, the moist air inside the unit must be evacuated to provide a proper internal environment, in order to obtain a reliable Dew Point measurement. In order to do this, either one of two methods may be used.



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• One is to fill the unit with dry nitrogen or air with dew point of –58°F/ 50°C or lower, to 2 psi, wait for 15 minutes and release the pressure; this process must be repeated one more time before the final pressurization for the test.

• The other method is to pull vacuum (2 Torr/2000 µHg) for 1 hour, break the vacuum and pressurize the transformer at 5 to 7 psi for 24 hours, with dry air or nitrogen with dew point of –58°F/ 50°C or lower. Then perform leak test and take dew point reading as specified below.

3C.3.1 Flanges and Threaded Joints Verification.

Using a soapy water solution, a commercial solution like Snoop™ or a leak detection instrument and while the transformer is under pressure, verify proper sealing on all flanges and threaded joints components that were assembled. If the transformer was received with zero pressure, a leak could be present on the components or valves that were not removed for shipment at the factory that could have been caused by the transportation. A leak test is required to confirm a proper sealing.

3C.3.2 Pressure Decay / Variation.

A small variation up to 1 psi in pressure may occur in the first 12 to 24 hours due to temperature variations. The unit must hold pressure for a 24-hour period.

3C.4 Moisture Content Verification.

The dew point must be measured 24 hours after completing the leak test to allow moisture equilibrium to occur inside the unit. This reading is necessary to calculate the moisture content of the transformer. This only applies when the insulation temperature is above 10°C. GE PROLEC requires that the moisture content does not exceed 0.5%. Moisture content greater than 0.5% will require an additional vacuum dry-out process prior to vacuum oil filling. If the insulation temperature is below 10°C or the moisture content is greater than 1.8%, a special dry-out process is required.



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The following flow chart should be used to decide the proper vacuum dry-out process needed.

Leak Test @ (5 – 7 p.s.i.)

Moisture content verification

Yes

No

Yes

No

Yes

No

Less than or equal than

0.5%?

Temperature below 10°C?

Hot oil dry-out process

(According to the Appendix Section)

Greater than or equal to 1.8%?

Vacuum dry-out process

(According to Section 3C.6)

Vacuum filling process

(According to Section 3C.7 or

3C.8)

Vacuum dry-out and oil filling flowchart.



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3C.5 Transformer Vacuum Process Preparation

3C.5.1 Grounding

The transformer must be securely grounded before beginning any vacuum process activities. A temporary ground wire must be connected on all bushing terminals to ground.

3C.5.2 Valve Positioning

The following valves must be closed: - Sudden Pressure Relay valve - Hydran Monitor valve - Desiccant canister valve - Drain and Fill Valves

The following valves must be opened: - Radiator valves - Pump valves - Main tank to Conservator (see special instructions for conservator filling) - Equalizing valve between conservator and bladder - LTC equalizing tube (if applicable). (refer to Figure 3-13)

LTCcompartment

Vacuum equalizingtube

Gas connection block

ConnectionforLTC units

LTC connectioncoupling

ABB type UZE LTC

The LTC connection coupling is located in one side of the compartment.

LTCcompartment



Gas connect ion block


ABB type UZF without Conservator

The LTC connection coupling is located in upper part of the compartment.

Figure 3 -13 Typical Location of Equalizing Tube in Load Tap Changers



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Gas connection block


LTCcompartment



ABB type UZF with conservator

The LTC connection coupling is located in flange of the conservator tank.

Gas connect ion block

Vacuum equalizing tube

LTCcompartment


LTC connect ioncoupling

MR type “ RMV” The LTC connection coupling is located in one side of the compartment.

MR type “M” and “MS”

This LTC is provided with two flanges, which have to be interconnected with each other.

Figure 3 - 13 (continuation) Typical Location of Equalizing Tube in Load Tap Changers



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• Never begin a vacuum process unless the LTC equalizing tube is in place and open. • Never break or pull vacuum through the LTC. Always use the appropriate valves and openings on the

main tank to pull or break vacuum.

3C.5.3 Bushing Connections

In order to avoid any stress or damage to the bushings during vacuum, there must be no rigid connections from the incoming/outgoing power lines to the bushing terminals.

3C.5.4 Gauges

A vacuum gauge must be installed on the main tank of the transformer for monitoring the vacuum level during dry-out process and oil filling. If a gauge is installed at the vacuum pump, it may give a false indication of the vacuum established within the transformer. It’s strongly recommended to use a thermocouple type gauge (Hastings, Stokes, Edwards). DO NOT USE A VACUUM METER CONTAINING MERCURY. Mount the vacuum gauge as close to the transformer’s tank as possible, installing it in a way that allows taking vacuum readings, even when the vacuum hose valve located at the tank is closed. A typical location for this gage is in the vacuum hose connection manifold.

It is recommended to connect a clear hose on the main tank bottom drain valve. This provides a sight gauge to monitor oil filling in a conservator type transformer, as these transformers do not have an oil level gauge installed on the main tank. This hose is vital in stopping oil flow when the level is within 12 inches of the main tank cover (References Section 3C.8 Vacuum filling process with conservator).

3C.5.5 Oil Testing before Filling Process.

The oil received from the supplier must comply with the characteristics listed in Table 1 of IEEE Std. C57-106-2002. Since doing a complete laboratory analysis in the field is not practical, the following acceptance criterions are provided as a reference, which can be done with portable equipment:

• Dielectric strength:

Minimum acceptance value must be 35 kV (according to ASTM D1816-97, 2mm gap) or Recommended sampling and testing procedure is as follows: 1. Care must be taken while obtaining the samples to avoid contamination. The sample container

must be glass type, clean and dry. 2. Five tests from the same sample should be performed. All the results must meet or exceed the

above-mentioned limit. 3. The oil sample must be idle for 5 minutes before starting each test. Each test shall be

performed at intervals of 5 minutes. Be aware that carbon deposits on the electrodes, might reduce critical distances and must be cleaned to provide accurate results. Refer to (ASTM D3613-98).

• Oil Power Factor value (where the equipment is available) should be 0.05% max at 25ºC (ASTM

D924-99e1).

For more detail on recommended oil properties, refer to the “Recommended Tests and Reference Values for Transformer Mineral Oil”, included in the Appendix section of this manual.



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GE PROLEC makes no representation or warranties express or i

3C.6 Vacuum Dry-Out Process

This procedure applies for units with moisture content greater than 0.5% and less 1.8%. The insulation temperature must be equal or greater than 50°F.

Step 1 Start vacuum pump

Step 2 When the vacuum level reaches 1 TORR (1000 microns) in the transformer; perform a vacuum drop test to verify no leaks are present in vacuum piping system. A. “Blank-off” the pump by closing its valve (3), the transformer valve (1) and maintain the vacuum pump

running. Verify the vacuum level in the vacuum meter installed on the pump. The pressure should drop drastically reaching 50 µHg or below within 5 to 10 minutes.

B. Open the valve (3) and verify the sealing within the hose. The pressure should maintain at least 50 µHg, otherwise a leak is suspected.

C. Open the transformer valve (1) wait 5 minutes for the pressure to stabilize in the transformer. Record the vacuum level reached.

D. Wait exactly 15 minutes after the pressure has stabilized and re-check the vacuum level in the transformer. E. The difference between the 5 and 15 minutes readings is used to calculate the leak rate. If the leak rate

exceeds 10 torr-gallons per second, then a leak on the transformer is present. Break the vacuum and identify/repair the leak.

To calculate the leak rate use the following equation:

900*VPL =

F. Repeat Step 2 until leak rate value is

Step 3 Continue the vacuum cycle until th

Base Rating ≤ 40

A≤ 2

Ambient Temperature during the Process < 70 °F

Vacuum Level to be reached 150 µHg Hold Period after reaching

Vacuum Level 48 hrs.

Vacuum Drop Test 100 µHg / 0.5 hrs

Proc

The vacuum drying process is considered the vacuum level has been reached and

compliesNotes:

1) 1000 µHg = 1 TORR = 1 mmHg 2) The Vacuum Drop Test is performed while the

transformer and recording the vacuum levesubtraction of the half hour value minus the firs

Table 3C. 1 Vacuum

Maintenance. Likewise, GE PROLEC shall not assume any responsinformation does not intend to cover all the details of the equipmemaintenance. Professional expertise is a requirement for every personor particular subject, please contact GE PROLEC Service DepartmentRev. 1 –Updated the entire document. December 8th, 2005 All rig

Where: P= Pressure change (torr) V= Total volume of oil (in gallons obtained from name plate)L= Leak rate (torr-gal/sec)

mplied, with respect to any information contained in this Manual of Installation, Operation and

below 10 torr-gallons per second.

e level specified in the following table is reached:

MVA ND 30 kV

> 40 ≤ 120 MVA AND

≤ 230 kV

> 120 MVA OR

> 230 kV

>= 70 °F < 70 °F >= 70 °F < 70 °F >= 70 °F

250 µHg 150 µHg 200 µHg 150 µHg 200 µHg

72 hrs. 72 hrs. 84 hrs. 72 hrs. 84 hrs.

100 µHg / 0.5 hrs

100 µHg / 0.5 hrs

100 µHg / 0.5 hrs

30 µHg / 0.5 hrs

50 µHg / 0.5 hrs

ess Termination Criteria

successful when all three criterions have been met. That means held during the specified hold period and the vacuum drop test with the specified drop value.

transformer is under vacuum. It is performed by closing the vacuum valve on the l at the transformer every 5 minutes during half hour. The test value is the t value, just after closing the valve (zero time value).

cycle requirements for dry-out process.

ibility or have any liability resulting from the selection or use of this Manual, by any person. This nt nor does it try to provide the procedures for every contingency of installation, operation and with the task of handling a power transformer. If you require additional information on any problem

. Phone: 1-800-437-7653. Fax: x 2011 Copyright © 2005

hts reserved, PROLEC GE IOMM-ENG

of 114



Step 4 Maintain a record log, provided in the Section 7 of this manual, during the entire process. It is mandatory to record and keep this information for future warranty purposes.

Step 5 Once the vacuum dry-out process is completed proceed to vacuum oil fill the transformer according to the Section 3C.7 for transformers without conservator or Section 3C.8 for transformers with conservator.

3C.7 Vacuum Filling Process for Transformers without Conservator

This procedure must be followed when the obtained moisture content result is less than or equal to 0.5%. All hose equipment for this process must be clean before making any connection.

Figure 3 - 14 Oil filling under vacuum process equipment setup



IOMM-ENG of 114


GE PROLEC makes no representation or warranties express or implie

Note: Steps 3 and 4 are not applicable if a dry-out process has been previously performed.

Step 1 All transformers should be filled through top filling valve (Figure 3-14, Valve 2).

Step 2 Close all valves except 1 and 7. Verify that the LTC equalizing tubing is in place and, if applicable, its valves are opened.

Step 3 Start vacuum pump and slowly open valve 3.

Step 4 When the vacuum level reaches 1 TORR (1000 microns) in the transformer; perform a vacuum drop test to verify no leaks are present in vacuum piping system. A. “Blank-off” the pump by closing valve 3 and maintain the vacuum pump running and verify the vacuum

levels in the vacuum meter installed on the pump. The pressure should drop drastically reaching 50 microns or below within 5-10 minutes.

B. Open valve 3 and close valve 1, this is to verify the sealing within the hose. The pressure should maintain at least 50 microns, otherwise a leak is suspected.

C. Open valve 1 and wait 5 minutes for the pressure to stabilize in the transformer. Record the vacuum level reached.

D. Wait exactly 15 minutes after the pressure has stabilized and re-check the vacuum level in the transformer. E. The difference between the 5 and 15 minutes readings is used to calculate the leak rate. If the leak rate

exceeds 10 torr-gallons per second, then a leak on the transformer is present. Break the vacuum and identify/repair the leak.

To calculate the leak rate use the following equation:

900*VPL =

F. Repeat Step 4 until leak rate value is be

Step 5 Open valve 3 and continue vacuum c

COLUMN 1 BIL (KV) Up to 35

Initial Vacuum Level 2 TORRMaintain Vacuum During Oil Filling 2 TORR

Wait Period Before Energizing (Soaking Time) 8 Hours

1000 µH

Table 3C. 2 Vac

Step 6 Turn on the degasifying equipment.

Step 7 Start oil flow by opening valves 4, 5 a

Step 8 The oil temperature must be 50 to 60

Step 9 Open valve 2 and maintain vacuum le

Maintenance. Likewise, GE PROLEC shall not assume any responsibilityinformation does not intend to cover all the details of the equipment nmaintenance. Professional expertise is a requirement for every person witor particular subject, please contact GE PROLEC Service Department. PhoRev. 1 –Updated the entire document. December 8th, 2005

CAll rights


d, with respect to any information contained in this Manual of Installation, Operation and

low 10 torr-gallons per second.

ycle according to the following table:

2 3 4 0 450 to 550 650 to 750 825 to 1425 1 TORR 0.5 TORR 0.25 TORR 2 TORR 1 TORR 1 TORR

12 Hours 24 Hours 48 Hours

g = 1 TORR = 1 mmHg

uum Oil Filling Requirements

nd 6.

°C while being introduced to the transformer.

vel specified in Table 3C. 2 Vacuum Oil Filling Requirements.

or have any liability resulting from the selection or use of this Manual, by any person. This or does it try to provide the procedures for every contingency of installation, operation andh the task of handling a power transformer. If you require additional information on any problemne: 1-800-437-7653. Fax: x 2011 opyright © 2005 reserved, PROLEC GE

IOMM-ENG of 114



Step 10 Maintain at least 2 psi on the outlet of the oil processing equipment and do not exceed 30 gallons per minute fill rate.

Step 11 When the liquid level gage (and/or sight tube) indicates that the oil level has reached the 25ºC indication, stop the pump and close valve 2. Note: Consider the oil temperature for the level corrections.

Step 12 Close all valves and break the vacuum with dry air or nitrogen (dew point of –58°F/ 50°C or lower) until reach positive pressure.

Step 13 Remove the vacuum hoses and pipes. Install all remaining components such as pressure relief devices and fill valve plug.

Step 14 If the transformer has a LTC remove equalizing tubing and install the supplied male plug on valve. Fill LTC to 25°C oil level indication. Note: Consider the oil temperature for the level corrections.

Step 15 Raise transformer internal pressure to 5 psig with dry air or nitrogen (dew point of –58°F/ 50°C or lower), and apply soapy water solution to detect possible leaks on the accessories installed after the vacuum process, located in the gas space. If none are found, continue with process. Repair any detected leaks.

Step 16 If the leak test is successful; lower the internal tank pressure to 2 psig.

3C.8 Vacuum Filling Process for Transformers with Conservator

This procedure must be followed when the obtained moisture content result is less than or equal to 0.5%. All hose equipment for this process must be clean before making any connection.

Figure 3 - 15 Typical Oil Processing Equipment Setup on a Transformer with Conservator Tank



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Figure 3 - 16 Process Equipment Setup for Oil Filling Under Vacuum

Note: Steps 3 and 4 are not applicable if a dry-out process has been previously performed.



IOMM-ENG of 114


GE PROLEC makes no representation or warranties express or implie

Step 1 All transformers should be filled through top filling valve (Figure 3-16, Valve 2).

Step 2 Close all valves except 1, 7, 9 and 10. Verify that the LTC equalizing tubing is in place and, if applicable, its valves are opened.

Step 3 Start vacuum pump and slowly open valve 3.

Step 4 When the vacuum level reaches 1 TORR (1000 microns); perform a vacuum drop test to verify no leaks are present in vacuum piping system.

A.

d on pump. The pressure values should drop drastically reaching 50 microns or below within 5-10 minutes.

B. Wait 5 minutes for the pressure to stabilize in the transformer. Record the vacuum level reached.

C. Wait exactly 15 minutes after the pressure has stabilized and re-check the vacuum level in the transformer.

D.

ds 10 torr-gallons per second, the transformer has a leak. Break the vacuum and identify/repair the leak.

E. Repeat Step 4 until a leak rate value below 10 torr-gallons per second is obtained.

To calculate the leak rate, use following equation.

“Blank-off” the transformer from the pump by closing valve 3. Maintain the vacuum pump on and verify the vacuum levels in vacuum meter installe

The difference between the 5 and 15 minutes readings are used to calculate the leak rate. If the leak rate excee

900*VPL =

Step 5 Open valve 3 and continue vacuum c

COLUMN 1 BIL (KV) Up to 35

Initial Vacuum Level 2 TORRMaintain Vacuum During Oil Fill 2 TORR

riod Before Ener 8 HoursWait Pe gizing (Soaking Time)

1000 µH

Table 3C. 3 Vac

• Make sure equalizing valve between conservator tank and bladder is completely open; otherwise, severe damage to the bladder will occur.

• Make sure equalizing tubing between LTC and main tank is installed and valves are opened, otherwise severe damage to LTC terminal board may occur.

Maintenance. Likewise, GE PROLEC shall not assume any responsibilityinformation does not intend to cover all the details of the equipment nmaintenance. Professional expertise is a requirement for every person witor particular subject, please contact GE PROLEC Service Department. PhoRev. 1 –Updated the entire document. December 8th, 2005

CAll rights


d, with respect to any information contained in this Manual of Installation, Operation and

ycle according to the following table:

2 3 4 0 450 to 550 650 to 750 825 to 1425 1 TORR 0.5 TORR 0 .25 TORR 2 TORR 1 TORR 1 TORR

12 Hours 24 Hours 48 Hours

g = 1 TORR = 1 mmHg

uum Oil Filling Requirements

or have any liability resulting from the selection or use of this Manual, by any person. This or does it try to provide the procedures for every contingency of installation, operation andh the task of handling a power transformer. If you require additional information on any problemne: 1-800-437-7653. Fax: x 2011 opyright © 2005 reserved, PROLEC GE

IOMM-ENG of 114



Step 6 Turn on the degasifying equipment.

Step 7 Start oil flow by opening valves 4, 5 and 6.

Step 8 The oil temperature must be 50 to 60°C while being introduce to the transformer.

Step 9 Open valve 2 and maintain vacuum level specified in Table 3C. 3 Vacuum Oil Filling Requirements.

0Step 1 Maintain 2 psi on the outlet of the oil processing equipment and do not exceed 30 gallons per minute fill rate.

Step 11 When sight tube indicates that the oil level is within 12 inches of the cover, stop oil filling and close valve 2. Stop vacuum pump. Break the vacuum with dry air or nitrogen (dew point of –58°F/ 50°C or lower).

Step 12 Install pressure relief device or blanking plate to close vacuum access.

Step 13 Remove equalizing tubing between LTC and main tank (if applicable), install supplied male plug on valve and fill LTC to 25°C level gauge indication. Note: Consider the oil temperature for the level corrections.

Step 14 Open valve 2. Fill conservator tank until the proper oil level is reached.

Step 15 The oil level gauge should register 25°C or higher depending on oil temperature.

Step 16 Inject 1.0 psig into the conservator bladder; oil should discharge from the valve 8. (It is recommended to install a hose to recollect the expelled oil in an appropriate oil container). Once this procedure has been completed, install the male plug on the valve. Finally, adjust the oil level so the gage corresponds to the oil temperature. Consider the oil temperature for the level corrections.

Step 17 Close valve 2 and remove fill line.

Step 18 All flanges, located on the transformer cover, that are not connected to the vent piping tubing should be air bled.

C.9 Post Filling Operations

B. C, verify that the oil cup on the bottom of the desiccant canister has been filled with oil to the red line.

D. aint that was damaged during transit and assembly should be “touched-up” with the paint kit

lay, bleed-off any air trapped in the piping.

G. If the unit is equipped with a Hydran Monitor, slowly bleed the device. Refer to OEM instruction book.

3

A. Remove temporary grounding from bushing terminals. If the transformer unit has a conservator or a LT

Remove the plastic plug from the silica gel canister.

C. Shipping blanking plates should be stored for possible future use. External Pprovided.

E. If the unit has a Bucholz or a gas detector reF. Slowly open sudden pressure relay valves.



IOMM-ENG of 114



Section 4 Pre-Start up Inspections

After the transformer has been assembled and oil filled, electrical routine commissioning tests must be done to confirm that the transformer is in operating condition. This section provides the guidelines to achieve a successful energization. The Section 7 includes a checklist form that has to be filled out during this stage of the process. Keep and send a copy of this information to GE PROLEC for future warranty purposes. 4.1 Paint Application

Once the assembly is finished, scratched or damaged areas of the transformer must be repainted with finishing paint after the surface is correctly prepared. The standard painting system is as follows (unless another painting system is specified):

• A primary coat of zinc epoxy-polyamide paint having approximately 2 to 3 mils in dry thickness.

• A high solid vinyl coat of finishing paint having 2 to 3 mils in dry thickness.

All the units are shipped with a touch-up paint kit, for additional information refer to the Appendix Section.

Figure 4 - 1 A typical installation of a Generator Step-up Power Transformer



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4.2 Electrical Tests

Recommended test recording forms are included in Section 7. A reference to testing and other standards is included in the Appendix Section of this manual.

4.2.1 Oil Dielectric Properties

Once the oil filling process is completed, perform an oil quality test. Oil samples must be taken from the drain valve (sampler valve). Drain ¼ gallon of oil before obtaining an oil sample. Perform the following tests:

4.2.1.1 Oil Dielectric Strength.

Oil breakdown voltage must be in accordance with the following table (ASTM D1816-97).

≤69 kV >69 kV

<230 kV ≥230 kV <345 kV

345 kV and above

1 mm gap 25 30 32 35 2 mm gap 45 52 55 60

4.2.1.2 Water Content.

The acceptance limit must be according with the following table. Oil temperature during sampling must be recorded

≤69 kV >69 kV

<230 kV ≥230 kV <345 kV

345 kV and above

20 mg/kg maximum

10 mg/kg maximum

10 mg/kg maximum

10 mg/kg maximum

4.2.1.3 Power Factor.

The results must be less than or equal to 0.05% @ 25°C and less than or equal to 0.3% @ 100°C.

A DGA should be performed in order to have a base line record. The oil sample for the DGA must be taken with a glass syringe.

4.2.2 Insulation Resistance

All primary and secondary external lines must be disconnected from the transformer bushings prior to performing insulation resistance measurements.

All insulation resistance readings must be corrected to 20° C. Perform insulation resistance measurements using 2500 to 5000 VDC. Maintain a steady voltage for all connections.

In order to correct the obtained readings to 20°C refer to the Appendix Section.

4.2.3 Insulation Power Factor

The insulation temperature greatly affects the obtained results therefore the results must be corrected to 20°C. The insulation power factor is also referred to as the dissipation factor, which technically is the



IOMM-ENG of 114



cotangent of the angle, where as the power factor is the cosine of the angle. These two values are approximately equal for very small angles. The most commonly used method for obtaining the insulation power factor is to use a 10 KV source voltage, which counteracts interference by induced voltages. A common device employed is a Doble Test Set.

The acceptance power factor value, once corrected to 20°C, must be equal or below 0.5%.

4.2.4 Transformer Turns Ratio (TTR)

TTR (Transformer Turns Ratio) is the ratio of the number of turns between high voltage and low voltage windings. When performing this test, measure the turn ratio of the windings at each tap position. If the transformer has load tap changer, measure the ratios throughout the entire LTC positions. The TTR values must be compared to the factory test results.

TTR values obtained must be within ± 0.5% of the calculated nameplate ratio values.

While using a direct current source on transformer windings, DO NOT open the circuit until the transformer is grounded. Failure to follow this instruction can lead to personal injury or severe equipment damage.

4.2.5 Core Insulation Resistance to Ground.

Use a 500 or 1000 VDC insulation resistance meter (MEGGER) to verify that the insulation between the main core and the frame is at least 200 MΩ. The core ground bushing is located inside a small box on the cover or the sidewall of the tank. Check the outline drawing for reference on the exact location of this box for your particular transformer. Also, when used, check all reactor cores to ground.

4.2.6 Bushing Power Factor.

The main purpose of this test is to find not only serious defects on the bushing that can have immediate consequences, but also incipient defects that could get gradually worse and ultimately result in a major failure of the bushing. Capacitance and power factor (dissipation factor) of the C1 and C2 capacitors must be measured if applicable. Compare the obtained values to the factory test results and nameplate of the bushing.

4.2.7 Excitation Current.

Perform a 10 kV single-phase excitation current test in accordance with the same tap positions tested at the factory. The usual approach to the analysis of the excitation current test results is to compare the results with the previous test, or with similar single-phase transformers, or with phases of a given three-phase transformer. For the majority of three phase transformers, the pattern is two similar high readings on the outer phases and one lower reading on the center phase.

4.2.8 Current Transformer Final Tests.

All current transformers should be tested on ratio, polarity, insulation resistance and saturation. The filed obtained results must be compared vs. the factory test data.



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4.2.9 Winding Resistance Test (Ohmic Resistance).

Winding resistance is measured in the field to assure the absence of problems related to loose connections, broken strands, and high resistance in tap changer contacts. Variation within 5% vs. factory test results is considered satisfactory. Because direct currents (DC used to perform winding resistance measurements) tend to saturate and polarize the core, all winding resistance measurements must be performed after the 10kV exciting current tests.

IMPORTANT Winding resistance test must be the last test performed in order to avoid magnetizing effects on the

core that could affect the results of other test.

4.2.10 Control Circuit Tests.

Perform an insulation resistance and continuity test on all control cabinet circuits except auxiliary equipment with solid state devices such as: Hydran, Electronic Monitor, LTC Beckwith Control, or any other electronic device. GE-PROLEC recommends using no more than 500 VDC to perform the insulation resistance test to the control wiring.

4.2.11 Alarm Test.

All alarm and trip signals from the transformer protective devices such as, buchholz, seal in relay, sudden pressure relay, pressure relief relay, winding temperature indicator, oil temperature indicator, oil level indicator, etc, should be tested for proper operation.

4.3 Final Inspection

4.3.1 Leak Verification.

All seals and gasket joints must be checked to assure no leaks are present. If the area to be checked is filled with gas (dry air or nitrogen), the leak check can be performed using soap and water. If the area to check is under oil, the leak check is just a visual examination to verify the absence of oil leaks.

4.3.2 Oil Level Gage.

Oil should be checked for proper level on bushings, main tank and load tap changer if so equipped.

4.3.3 Fans and Pumps.

Fans and pumps should be checked for manual and automatic operation. Confirm proper fan blade rotation. If fans and pumps have improper rotation switch two of the three-phase line leads from the power supply.



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4.3.4 Valves.

Assure all valves are in the right position prior to energizing, for example: Radiator valves: Open Conservator tank valve: Open Equalization valve (Conservator and bladder): Closed Equalization tube (Main tank and LTC tank): Valves should be closed Silica Gel valve: Open Drain and fill valve: Closed

4.3.5 Temporary Grounds.

Prior to energizing and after draining the static charges, confirm all temporary personnel safety grounds from all bushings have been removed.

4.3.6 Final Ground Connections.

Verify that all final grounds are connected and have no loose connections. Ground connections include neutral bushing ground bus, tank to site ground mass (a minimum of 4/0 copper cable should be installed), control cabinet and accessory grounds.

4.3.7 Surge Arresters.

Confirm proper ground connections of surge arresters and accessories (discharge counters). Be sure the pressure relief vents are pointing away from the transformer.

4.3.8 De-energized Tap Changer.

De-energized tap changer should be checked to confirm a smooth operation and restored to the nominal primary voltage position. GE PROLEC standard practice is to ship the transformer with the de-energized tap changer in the nominal position.

Record the initial position when the unit is ready to be energized.

4.3.9 Load Tap Changer.

Load tap changer must be tested through all its step positions. Confirm the absence of moisture in the silica gel by means of a visual inspection. If silica gel is pink or pale yellow, it indicates moisture saturation and must be replaced or dried using an external heating device.

Confirm LTC to main tank pressure - vacuum equalization line has been removed.

4.3.10 Current Transformer Verification.

Confirm current transformer terminal blocks either are with burden or short-circuited.



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4.3.11 Control Cabinets.

Proper operation of the following accessories should be verified: space heater, interior lighting.

4.3.12 Materials and Tools.

Assure that no foreign materials or tools remain on top of the transformer.

4.3.13 Main Tank Silica Gel Canister.

Confirm the absence of moisture in the silica gel by means of a visual inspection. If silica gel is pink or pale yellow, it indicates moisture saturation and must be replaced or dried using an external heating device.



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Section 5 Transformer Operation and Maintenance Guide

Operation In order to obtain a long operational life span and warranty purposes of the power transformer, it is recommended to operate it at a capacity not greater than the design rating. The transformer should operate with a normal oil level and adequate ventilation; this eliminates overheating and prevents early deterioration. 5.1 Service Conditions

Transformer data service conditions are stated on the nameplate.

5.1.1 Altitude

The transformer must operate at no more than the altitude stated on the nameplate. Operating at higher altitudes will reduce cooling capacity and dielectric distances.

5.1.2 Ambient Temperature

The design temperature limits should not be exceeded. Unless otherwise specified, the transformer is designed to operate at an ambient temperature of 30°C average and 40°C maximum (as per ANSI C57.92.1981). If the transformer is operated exceeding its maximum designed ambient temperature limits, it is strongly recommended to reduce its capacity, according to the following table:

Type of Cooling System Percent of Reduction in KVA for each °C

Oil Filled, forced air, ONAF 1.0 Oil Filled, self cooled, ONAN 1.5 Forced oil, forced air, OFAF 1.0

Table 5.4 – Reduction in capacity due to high ambient temperature

5.2 Voltage Variation Conditions

Transformer should not be operated exceeding the 5% nameplate nominal rated voltage, according to ANSI C57.12.00.

Never attempt to operate the de-energized tap changer when the transformer is energized. Severe damage will occur to the transformer and operator.

5.3 Variation of the Auxiliary Voltage.

Auxiliary power supply for transformer devices (auxiliary equipment) should not exceed variations of ±10%.



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5.4 Overload Conditions

Transformers may operate at greater loads than the rated capacity for short periods without any damage that would affect the life insulation system.

For additional information, refer to ANSI-C57.91 IEEE Guide for Loading Mineral-Oil-Immersed Power Transformer.

When a problem occurs in the cooling system of a transformer, capacity is reduced. Refer to the Appendix (Quick Continuous Capacity Decision Chart).

5.5 Self Cooled Transformer (ONAN).

If a radiator valve is closed, the continuous capacity of a self-cooled transformer can be calculated in the following manner:

[ ] 100*

)1(1(%) ×+

−=RNRnCapacityContinuous

Where: N = The total number of radiators n = The number of radiators that were removed or valves closed R = (Copper losses / Core losses) at full rated load.

5.6 Transformer with Forced Cooling System (ONAF or OFAF).

When the forced air-cooling system is out of operation or a pump is out of service, the following considerations should be taken:

If a fan is turned off, the continuous capacity of a self-cooled transformer can be calculated in the following manner:

[ ] 100*

)1(1(%) ×−

−=RN

RnCapacityContinuous

Where: N = The total number of fans n = The total number of fans that are not functioning. R = (Copper-ONAF losses / Copper-ONAN losses) at full rated load. In the case of an ONAN/ONAF/OFAF system, if the pumps are not functioning; the system may operate as an ONAN/ONAF/ONAF.



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Maintenance Periodic maintenance and inspections will contribute to safe, reliable and trouble free operation of a transformer. The following inspections may detect potential operational problems before they become critical and will maintain the warranty.

Frequency No Concept Weekly Monthly Every Six

Months Every Year Every Five Years

1 General Inspection X X 2 Oil Tests O 3 Routine Electrical Tests O 4 Transformer Protective

Devices Tests O

5 External Inspection O (A) O (B) 6 Internal Inspection X

Notes:

• All checklists are located in Section 7. • Inspection procedures marked with an “O” are considered mandatory. • The letters A and B of the external inspection refer to the applicable checklist. The inspection items marked

with the letter A may be performed while the transformer is energized; while the items marked with the letter B must be performed when the transformer is de-energized.

Table 5. 5 – Maintenance activities and time intervals table.

5.7 Safety Procedures during Internal Inspection and Maintenance or Repairs.

Before doing any internal inspection, maintenance procedure or repair in the transformer, the following safety guidelines must be considered. Also, refer to Section 2 of this manual for additional safety requirements.

• De-energize the transformer by disconnecting both High and Low Voltage lines. • Ground the terminal lines of the transformer. • Place locks and warning cards stating that the interrupters or terminal boxes must not be operated (LOTO

procedures). • Disconnect the power supply of the control cabinet. • Before going inside to any transformer, verify that the internal environment contains a minimum of 19.5%

oxygen and maximum of 50 ppm CO for exposures up to 8 hours period. For further information, refer the OSHA regulation. Utilize dry air (less than 0.05% impurities and - 58°F/- 50°C or lower dew point) for flowing through the transformer while inside the transformer tank.

• Use only explosion proof lamps inside the tank and verify the insulation condition of the electrical cord, it must be free of damage.



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Section 6 Statement of Environmental Accessory Transformer Components

A power transformer is comprised of several parts and materials related to each other. The containment vessel or tank, the core & coils assembly and accessory components make up a set of pieces that put together form a transformer. The main materials used to manufacture these parts are as follows:

Metals: Mild steel, stainless steel, zinc, silver alloy, cast aluminum, brass.

Fluid: Mineral (NON-PCB) Oil.

Plastic: Phenolics, nylon and other polymers including non-lead based paint.

Copper: Pure and alloyed.

Cellulose: Insulating paper and fiber structures.

Ceramic: Silica based material.

Wood: Native untreated North American pine for packaging.

Many of these materials have multiple secondary uses and others will have uses in the future. In disposing of a transformer consult with local regulating authorities and always feel confident to call GE-PROLEC for additional component information.

NOTES:

• The power transformers that are manufactured by GE-PROLEC are tested with transformer oil free of PCB’s (polychlorinated biphenyl). In the case where the transformer oil for operation is provided or treated by the user, it is recommended to always maintain the transformer free of PCB’s.

• For Material Safety Data Sheets, please refer to www.prolecge.com.



IOMM-ENG of 114

http://www.prolecge.com/



Section 7 Checklists

Main Data Customer

Unit Serial No. Number of phases and type of transformer

Capacity (MVA) High Voltage and Vector

Temperature rise (°C) Low Voltage and Vector

Cooling System Type (ONAN, ONAF, ODAF, etc.)

Date of this report (dd/mm/yyyy)

Site address

Number of HV tap changer positions

Number LV tap changer positions

Receiving Date (dd/mm/yyyy)

Assembly Date (dd/mm/yyyy)

Pre-start up inspection Date (dd/mm/yyyy)

Energization Date (dd/mm/yyyy)

ADDITIONAL COMMENTS:



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Receiving Inspection Check List Unit Serial No. Date

(dd/mm/yyyy)

Inspected at (location)

Transformer is on: Railroad Car Truck Platform Ground Installation Pad Other: __________________

ITEM CHECK POINT OR ACTION DONEREFERENCE OR

CRITERIA RECORDED

VALUE COMMENTS

BEFORE OFF-LOADING 1 Visual inspection of transformer. Damage in

tank walls, protruding parts, wood crates, accessories, control cabinet. Check if there are any oil leaks or loose tie downs.

Section 3A.3.1 If damage is found, follow procedure described in this section.

Take pictures of the unit.

2 Verify internal gas pressure of the transformer, record value.

Section 3A.3.1 Pressure: p.s.i.

3 Verify that the impact recorder is operating, mark needle position and sign off including date and time.

Section 3A.3.1 Store recorder chart for future reference

4 Perform an insulation resistance test (megger) of core to ground.

Must not be grounded Resistance: Mohms at Temp(°C)

5 Perform an insulation resistance test (megger) of clamps to ground (if applicable).

Must not be grounded.

Resistance: Mohms at Temp(°C)

6 Perform an insulation resistance (megger) of reactor to ground (if applicable).

Must not be grounded. Resistance: Mohms at Temp(°C)

7 Verify condition of de-energized tap changer. Section 3A.3.1



IOMM-ENG of 114




CRITERIA RECORDED

VALUE COMMENTS

DURING OFF-LOADING 8 Transformer maintained at the proper angle Section 3A.3.2

9 No more than 3 p.s.i. when lifting Section 3A.3.2

10 Lifted only from lifting lugs Section 3A.3.2

11 Proper jack positioning (if applicable) Section 3A.3.2

12 Transformer tank base sitting flat on concrete pad

Section 3A.3.2

AFTER OFF-LOADING 13 Electrical connections inside the control cabinet

are tight and the Manual is inside. Section 3A.3.3

14 Verify operation of de-energized tap changer Section 3A.3.3

15 Perform LTC and LTC Cabinet Inspection. Section 3A.3.3

16 Inspect radiator valves and transformer cover Section 3A.3.3

17 All the accessories, shipping crates and parts are complete and on site.

18 The transformer is grounded.


INSPECTED BY:

______________________________________ ______________________________________

NAME SIGNATURE



IOMM-ENG of 114



Storage Inspection Check List Unit Serial No. Date

(dd/mm/yyyy)

Storage Location

Estimated time the unit will be stored Less than 3 months Between 3 and 6 months More than 6 months


CRITERIA RECORDED

VALUE COMMENTS

1 Perform an external receiving inspection of the unit

Receiving inspection check list

Receiving inspection check list

FOLLOW THESE STEPS IF THE UNIT IS GOING TO BE STORED LESS THAN 3 MONTHS

2 Fill with nitrogen or dry air at 3 p.s.i. (-50°C / -58°F dew point or lower).

Section 3A.4 Filling pressure: ___________ p.s.i.

3 Check for leaks with soap and water. Section 3A.4

4 Verify all steel components have blanking plates installed (radiators, conservator tank, manifolds, pumps, pipes)

Section 3A.4

5 Verify all the bushings are stored in the proper position.

Section 3A.4

6 Verify all the crate boxes containing accessories are closed, undamaged and protected from the environment.

Section 3A.4. Not sitting directly on the ground.

7 Verify all the items in the Packing Lists are accounted for.

Packing Lists included in the shipment

8 Verify the proper operation of the nitrogen equipment (if applicable)

Nitrogen Equipment Operation Manual

9 Record pressure of the nitrogen bottle (if applicable)

Section 3A.4 Pressure: ___________ p.s.i.

10 Initiate the attached periodic pressure recording form and put it inside the Nitrogen Equipment cabinet. (if applicable)

See attached Periodic Pressure Recording Form

11 Stop the impact recorder, sign off and include date, time and transformer location.

Date & Time the impact recorder was stopped ___________ Date ___________ Time



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CRITERIA RECORDED

VALUE COMMENTS

FOLLOW THESE STEPS IF THE UNIT IS GOING TO BE STORED BETWEEN 3 AND 6 MONTHS

The same steps that are followed for less than three months of storage period. The difference is that if the transformer is going to be stored up to 6 months, the ONLY approved gas that may be used to fill the transformer is high purity nitrogen (-50°C / -58°F dew point or lower).

FOLLOW THESE STEPS IF THE UNIT IS GOING TO BE STORED FOR MORE THAN 6 MONTHS

12 Assemble and oil fill the unit according to Section 3 of this instruction book.

Section 3C

13 Verify the proper operation of the nitrogen equipment.

Nitrogen Equipment Operation Manual

14 Record pressure of the nitrogen bottle (200 psi minimum requires bottle change out).

Pressure: ___________ p.s.i.

15 Initiate the attached periodic pressure recording form and put it inside the Nitrogen Equipment cabinet.

See attached Periodic Pressure Recording Form

16 Stop the impact recorder, sign off and include date, time and transformer location.

Date & Time the impact recorder was stopped ___________ Date ___________ Time


INSPECTED BY:

______________________________________ ______________________________________

NAME SIGNATURE



IOMM-ENG of 114



Periodic Pressure Recording Form

Date & Time Transformer Pressure (p.s.i.)

N2 Bottle Pressure (p.s.i.)

Liquid Temperature Indicator reading (°C)



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Internal Inspection Check List Customer:

Unit Serial No. Date (dd/mm/yyyy)

Notes: 1) If any damage is found during internal inspection, GE-PROLEC should be immediately notified. 2) For the purpose of this list, “tight” means that it cannot be moved applying hand force. 3) Before anyone attempts to enter the transformer, the adequate oxygen and carbon monoxide contents

must be checked.

ITEM CHECK POINT OR ACTION DONE REFERENCE OR CRITERIARECORDED

VALUE COMMENTS

1 Verify adequate oxygen content Section 3B.2 Minimum: 19.5%

Oxygen content: %

2 Verify that the personnel going into the transformer is wearing the appropriate clothes.

Section 3B.2

3 Verify the quality of the purging air (-50°C / -58°F dew point or lower).

Section 3B.2

4 Record and verify the ambient relative humidity.

Section 3B.2

Ambient relative humidity: %

5 Record time of opening Time:

6 Inspection of core condition. Tight and undamaged laminations. Core ground in place.

Take pictures where possible.

7 Inspection of clamps and core-clamp insulation

All clamp bolts tight. Insulation tight and in its place. No loose ground straps between clamp pieces.


8 Inspection of current transformers. Tight installation. Insulation pieces not loose. Wiring in place and no visible damage due to transportation movement.

Take pictures where possible



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VALUE COMMENTS

9 Inspection of bushings Porcelain in good condition, no damage or cracks. Gasket in its groove. Connection electrostatic shield in good condition, no scratches or lack of insulation (if applicable). Connection terminal surfaces should be clean, flat and without scratches. Flexible connectors undamaged and securely tied with all bolts/washers accounted for. All leads securely tied and no damage to connector threads. No leaks.

Take pictures where possible

10 Internal hardware torque. Bushing connections torque. Torque tables are located in the Appendix Section.

LV Connector Foot-Pound HV Connector Foot Pound

11 Insulation pieces and support frames inspection.

All insulation pieces in place and tight. Nylon bolts are tight and in place. No cracked or damage wood structure pieces. No wood blocks loose. Transformer base free of debris or loose blocks. Pressboard pieces tight and in place.Remove any shipping braces. Absence of any abnormal looseness or movement caused by shipping. Hardware securing the unit in the tank and the winding jacking screws must be tight.


12 Inspection of jacking screws. Tight and cannot be loosened with hand pressure. Lock nut is tight.


13 Inspection of Load Tap Changer (LTC) (if applicable).

Leads are tight. No damage to leads insulation. No cracks or damage to the terminal board. No bolts touching each other.


14 Inspection of No Load Tap Changer (NLTC)

No signs of damage on NLTC structure and components. All stationary contacts are aligned and moving contact displaces freely on all positions. Shaft aligned and without signs of cracks or damage.


15 Inspection of main tank and/or conservator liquid level indicator.

The float arm swings freely. The float arm is tight.


16 Inspection of thermo well No visible damage and at least 2” distance from any lead




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VALUE COMMENTS

17 Reactor (if applicable) All the leads and insulation pieces in place and tight. All the leads are connected. No loose insulation. No damage on paper lead insulation.


18 Cleanliness No foreign materials inside the unit or on the floor of the transformer. All tools and materials have been removed from the interior and accounted for.


19 Entrance manholes have been resealed with new gaskets and leak tested.

Torque on manhole bolts Foot-pound

20 Unit re-pressurized with nitrogen or dry air (-50°C / -58°F dew point or lower).

Follow purging recommendations give in Section 3C.3

Pressure p.s.i.

21 Record time of closure Time:


INSPECTED BY:

______________________________________ ______________________________________

NAME SIGNATURE



IOMM-ENG of 114



Assembly Inspection Check List Customer:



CRITERIA RECORDED VALUE COMMENTS

1 Verify that all pieces and accessories are on site, nothing should be missing and / or damaged.

Packing list

2 Verify physical condition of all crate boxes, including bushings, accessories and radiators.

Free of damage, rust and cracks.

3 Open control cabinet and inspect all panels and internal accessories.

No parts missing and / or damaged. No signs of water condensation inside the cabinet.

4 Assembly instructions and recommendations of this Manual are shared and discussed with the assembly crew.

Installation, Operation and Maintenance Manual. All procedures and drawings.

5 Record torque values required on all hardware according to instruction book to the crew

Appendix Section Record applied torque to: LV Bushings ___________ Ft-Lb HV Bushings ___________Ft-Lb Manhole covers ___________ Ft-Lb Accessories ___________ Ft-Lb Radiator flanges ___________ Ft-Lb

6 Perform preliminary internal inspection Internal Inspection Check List

Internal Inspection Check List

7 Install radiator manifolds (if applicable) Section 3B.4

8 Install radiators Section 3B.4

9 Install support tension rods Section 3B.4

10 Install oil pump and assure proper oil flow (if applicable)

Section 3B.4



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11 Open conservator (if applicable) manholes. Inspect bladder seal and properly hanged. No obstruction to liquid level floater arm.

Section 3B.5

12 Install conservator base (if applicable) Section 3B.5

13 Install conservator (if applicable) Section 3B.5

14 Install conservator pipe to main tank, including required valves and Buchholz relay (if applicable)

Section 3B.5

15 Install Buchholz relay (if applicable) sample tubing

Section 3B.5

16 Install silica gel pipe and canisters (if applicable). This canisters have top and bottom shipping plugs that must be removed for operation

Section 3B.5

17 Install surge arrester base (if applicable) Section 3B .9.7

18 Open bushing turrets and perform a visual inspection of CT and seal gasket grooves (if applicable)

Section 3B.6 Insulation pieces in place. No visual indication of damage to CT.

19 Install bushing turrets (if applicable) Section 3B.6

20 Megger and ratio test CT. Section 3B.7 Insulation resistance: Record in separate form

21 Install LV bushings. Check torque table and discuss lift procedure

Section 3B.8 Flange torque ___________ Ft-Lb Internal connection torque ___________ Ft-Lb

22 Install HV bushings. Check torque table and discuss lift procedure. 345KV and above bushings could require the voltage deflector tube to also be installed.

Section 3B.8 Flange torque ___________ Ft-Lb Internal connection torque ___________ Ft-Lb

23 Ensure no temporary or shipping supports are inside the transformer. If there is any doubt, check the instruction book or contact GE Prolec.

24 Install surge arresters (if applicable).

25 Install surge arrester counters and their ground (if applicable).

26 Install vent pipe tubes (if applicable).

27 Install remaining applicable devices such as pressure relief devices (all but one that will be used for the vacuum process).

Section 3B.9



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28 Install sudden pressure relay (if applicable) if there is a valve between it and the tank. If no valve, then install it at the same time as the pressure relief device.

Section 3B.9

29 Install other gas accumulator device (if applicable)

Section 3B.9

30 Install ground resistor (if applicable) Section 3B.9

31 Applicable following valves are closed? Sudden pressure relay, Hydran sensor, desiccant cylinder, drain and fill valves

32 Applicable following valves are open? Radiators, manifolds, pumps, equalizing between conservator and bladder, equalizing between load tap changer and main tank

33 Perform final internal inspection Internal Inspection Check List

Internal Inspection Check List

34 Internal air has been purged or evacuated with a vacuum pump.

Section 3C.3

35 Pressure unit to 5 psi with dry air or nitrogen (-50°C / -58°F dew point or lower) for 24 hours.

Section 3C.3 Pressure ___________ p.s.i. Time ___________ hrs

36 Inspect all gasket joints with a soap and water solution to ensure no leaks are present.

Section 3C.3 Take pictures where possible

37 Take dew point reading after 24 hours wait time.

Section 3C.4 Dew point: _____________°C Insulation temp: ____________ °C Calculated moisture content: ____________ %

38 Calculate moisture content. Equal or below0.5%? If yes, then continue with steps. If no, then transformer is not dry enough and a special drying process should take place.

Section 3C.4

39 Initiate vacuum process Section 3.5 Date & Time ___________ ___________



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40 Vacuum level and drying hold time are according to instruction book.

Section 3C.5 Vacuum achieved ___________ µm Hg Held for ___________ hrs

41 Continue with oil fill procedure as described in instruction book.

Section 3C.5

42 Ensure bladder is properly inflated after oil filling the conservator.

Section 3C.5 Pressure applied to bladder

1 p.s.i.

43 Perform instruction book test. Appendix Record and include test results along with this check list

44 Inspect transformer for possible transportation, off loading and assembly paint damage, and do a touch up with the supplied paint kit.

Appendix

45 Remove all residual material/tools from transformer assembly.

46 Follow wait period recommended in instruction book prior to energizing.

Section 3C.5

47 Install Hydran monitor sensor and analyzer (if applicable). Close sensor valve

Section 3B.9


INSPECTED BY:

______________________________________ ______________________________________

NAME SIGNATURE



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Vacuum Process Log Customer:


Date & Time Vacuum Level

(microns- µHg) Ambient Temperature (°F)

Relative Ambient Humidity (%)

Date & Time Vacuum Level (microns- µHg)

Ambient Temperature (°F)

Relative Ambient Humidity (%)

Vacuum Drop Test Recording Chart Date and Time

Reading Time (minutes) Vacuum Level

1 0

2 5

3 10

4 15

5 20

6 25

7 30

Result calculation Reading 7 – 1=



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Pre-Startup Inspection Check List Customer:


Note: Before energizing your transformer for the first time, the following items must be fulfilled.



1 Inspect for any damage to the paint. If necessary repaint any scratch or damage to painted surfaces.

Section 4.1 See also the Appendix

2 Perform the minimum oil quality tests Section 4.2.1 Attach to this check list, any lab report, test form or document used to conduct the tests

See Section 7 for Oil Tests Recording Form

3 Perform an insulation resistance (megger) test.

Section 4.2.2 Attach insulation resistance test form to this check list

4 Perform Doble™ insulation power factor test.

Section 4.2.3 Attach insulation power factor test results to this check list

5 Perform a transformer turn ratio (TTR) test Section 4.2.4 Attach test results to this check list

6 Perform a cores/clamp grounds insulation resistance (megger) test

Section 4.2.5 Insulation resistance ___________ MΩ

7 Perform a power factor test to the bushings (if applicable)

Section 4.2.6 Attach test results to this check list

8 Perform an excitation current test with the DOBLE test set


9 Perform a ratio test to every tap, insulation resistance, saturation and polarity tests to the current transformers (CT)


10 Perform insulation resistance and continuity test on control wiring


11 Inspect the oil is at the proper level Section 4.3.2 When possible take a picture

12 Perform a manual and automatic functional test on the cooling system (fans and pumps)

Section 4.3.3

13 Check that all the valves are in the proper position

Section 4.3.4

14 Remove all temporary grounds from bushings and windings

Section 4.3.5



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15 Inspect all final ground connections Section 4.3.5

16 Inspect the surge arresters (if applicable) Section 4.3.7

17 Inspect de-energized tap changer (DETC) Section 4.3.8

18 Inspect load tap changer (LTC) (if applicable)

Section 4.3.9

19 Inspect control cabinets Section 4.3.11

20 Inspect conservator tank (if applicable) Section 4.3.13

21 Inspect sudden pressure rise relays (if applicable)

22 Inspect gas accumulator device (if applicable)

23 Inspect bushing condition

24 Check that no foreign materials or tools are left in the top of the transformer

25 Inspect for radiator debris and contamination

27 Test all protective and alarm devices Section 4.2.11


INSPECTED BY:

______________________________________ ______________________________________

NAME SIGNATURE



IOMM-ENG of 114



Maintenance Inspection Check Lists

General Inspection Recording Form

Customer:


ITEM CHECK POINT OR ACTION RECORDED VALUE COMMENTS

1 LTC Position Monitor (INCON) INCON ___________

LTC ___________

2 Number of LTC operations

4 Winding temperature readings HV ____________

LV ____________

5 Liquid temperature reading Temp ____________

6 Liquid level gage reading High _____

25°C _____

Low _____

7 LTC liquid level reading (if applicable) High _____

25°C _____

Low _____

8 Check pressure gauge (If applicable) Pressure _____ p.s.i.

9 Check the absence of oil leaks on all bolted and threaded joints

10 Bushing oil liquid level and color (If applicable) Level ___________

Color ___________

11 Readings of Hydran monitor (If applicable) Gas Level _____ ppm

Hourly Trend

_____ ppm/hr

Daily Trend

_____ ppm/day

12 Discharge counters No. discharges _____

13 Bushings and surge arresters porcelain conditions



IOMM-ENG of 114




14 Current cooling phase in operation

__ ONAN __ ONAF-1 __ ONAF-2 __ ODAF __ OFAF

15 Test alarm annunciator panel (if applicable) All lights are ok?

_____ Yes

_____ No

16 Check condition of silica gel in load tap changer and conservator tank; pale pink or pale yellow.

Condition ________

17 Check nitrogen gas cylinder pressure. Replace it when the pressure falls below 200 p.s.i.

_________ p.s.i.

INSPECTED BY:

______________________________________ ______________________________________

NAME SIGNATURE



IOMM-ENG of 114



Oil Tests Recording Form Customer:


Note: All samples for oil testing purposes must be obtained from the sampling port of the lower drain valve.

Physical and Chemical Properties

Sample Number: Sample Date:

Test Standard Value

Dielectric Strength ASTM 1816 __________ kV

Dielectric Strength ASTM D877 __________ kV

Power Factor @ 25°C ASTM D924 __________ %

Power Factor @ 100°C ASTM D924 __________ %

Specific Gravity ASTM D1298 __________

Color ASTM D1500 __________

Interfacial Tension ASTM D971 __________ ppm

Neutralization Number ASTM D974 __________ mgKOH / g

Water Content ASTM D1533 __________ ppm

INSPECTED BY:

______________________________________ ______________________________________

NAME SIGNATURE



IOMM-ENG of 114



Oil Tests Recording Form

Dissolved Gas Analysis Results Customer:


Sample Number: Sample Date:

Gas Symbol Value

Hydrogen* H2 __________ ppm

Methane* CH4 __________ ppm

Ethylene* C2H4 __________ ppm

Ethane* C2H6 __________ ppm

Acetylene* C2H2 __________ ppm

Carbon Monoxide* CO __________ ppm

Carbon Dioxide CO2 __________ ppm

Oxygen O2 __________ ppm

Nitrogen N2 __________ ppm

* - The asterisk denotes a combustible gas INSPECTED BY:

______________________________________ ______________________________________

NAME SIGNATURE



IOMM-ENG of 114



Maintenance External Inspection Recording Form Customer:



A – Energized Transformer (Date ___________) 1 Manually rise and lower the load tap changer using the

selector switch in the cabinet panel. Warning: This would modify the voltage output of the transformer.

2 Verify fans operation

3 Verify oil pump operation by turning them on and watching the oil flow indicator.

4 Check grounding system conditions. Verify everything is tight and corrosion free.

5 Check the inside of the main control cabinet and nitrogen bottle compartment (if applicable). Verify there is not

condensation inside the cabinets and the cabinet heaters are working correctly.

6 Check the absence of oil leaks on all bolted and threaded joints

B – De-energized Transformer (Date __________) 7 Verify external electrical connections for tightness and for

any sign of discoloration, indicating a hot spot. If there is any doubt, the suspicious connection should be cleaned and re-connected. If discoloration is extensive, further investigation

is recommended.

8 Check the absence of oil leaks on all bolted and threaded joints, specially on the transformer’s cover.

9 Inspect heat exchangers looking for any airborne debris or foreign material in the cooling surfaces. In case cleaning is required, it may be carried out using compressed air and/or

water.

10 Operation of de-energized tap changer (DETC)

INSPECTED BY:

______________________________________ ______________________________________

NAME SIGNATURE



IOMM-ENG of 114



Routine Electrical Tests Checklist

Customer:


Note: All electrical tests should be performed while the transformer is de-energized. Never attempt to test a transformer while it is energized, doing so may cause severe property damage or death.

ITEM CHECK POINT OR ACTION RECORDED VALUE DONE (YES/NO)

1 Thermography Pictures or Image File

2 Winding Resistance See Winding Resistance Recording Form

3 Insulation Power Factor See Insulation Power Factor Recording Form

4 Bushing Power Factor See Bushings Power Factor Recording Form

5 Excitation Current See Excitation Current Test Recording Form

6 Insulation Resistance See Insulation Resistance Recording Form



IOMM-ENG of 114



Winding Resistance Recording Form Customer:


High Voltage Windings Resistance (Ω) Test Temperature H ___ to H ___ H ___ to H ___ H ___ to H ___

Corrected @ _____ °C

Low Voltage Windings Resistance (Ω) Test Temperature X ___ to X ___ X ___ to X ___ X___ to X ___


Tertiary Voltage Windings Resistance (Ω) (if applicable) Test Temperature Y ___ to Y ___ Y ___ to Y ___ H ___ to H ___


Note: Winding resistance tests should be performed with the tap changer on the nominal position and on the highest and lowest positions. Perform winding resistance test after exciting current test are complete. INSPECTED BY:

______________________________________ ______________________________________

NAME SIGNATURE



IOMM-ENG of 114



Insulation Power Factor Recording Form

Customer:


Insulation Temperature (°C): Ambient Moisture: Correction Factor:

Test Voltage: Equipment Used: Equipment Serial No.:

Current Real Power %PF %PF Test equipment lead

connections Test

number E Gr G UST

Reading K mA Reading K W @ ____°C @ 20 °C

Capacitance (pF)

1

2

3

4

5

6

7

8

INSPECTED BY:

______________________________________ ______________________________________

NAME SIGNATURE



IOMM-ENG of 114



Bushings Power Factor Recording Form

Date: Equipment Used: Transformer Serial

No.

Test Voltage: Equipment

Serial No.: Test type C1 C2

Current Real Power %PF @ %PF @ Bushing

Label Serial Number Reading K mA Reading K W _____ °C 20 °C

Capacitance (pF)

INSPECTED BY:

______________________________________ ______________________________________

NAME SIGNATURE



IOMM-ENG of 114



Excitation Current Test Recording Form

Insulation Temperature (°C):

Date:

Transformer Serial No.


Used:

Tap Changer

Position H__ to H__

(mA) H__ to H__

(mA) H__ to H__

(mA)

INSPECTED BY:

______________________________________ ______________________________________

NAME SIGNATURE



IOMM-ENG of 114



Insulation Resistance Recording Form

Insulation Temperature (°C):

Ambient Moisture: Correction

Factor: Date:


Used: Transformer Serial No.

Time H / X + Gr (MΩ)

X / H + Gr (MΩ)

H + X / Gr (MΩ)

15 s

30 s

45 s

1 min

2 min

3 min

4 min

5 min

6 min

7 min

9 min

10 min

INSPECTED BY:

______________________________________ ______________________________________

NAME SIGNATURE



IOMM-ENG of 114



Transformer Protective Devices Test Recording Form

Customer:


ITEM CHECK POINT OR ACTION RECORDED VALUE /

DONE COMMENTS

1 Temperature protective relays Oil Temperature Indicator

Winding Temperature Indicator

2 Liquid level liquid protective relay

3 Pumps relays (If applicable)

4 Inert air alarms relays

5 Fans protective relays

6 Manually operate oil pumps (if applicable)

7 Operate annunciator panel test switches (if applicable)

8 Pressure relief device relays

9 Sudden Pressure relay

10 Bucholz relays

11 Protective LTC relay

12 Hydran

13 Other

INSPECTED BY:

______________________________________ ______________________________________

NAME SIGNATURE



IOMM-ENG of 114



Appendix Paint Kit A.1 - Touch-Up Painting Kit

As part of the supplied materials for Transformer Assembly, a touch-up painting kit is provided for each new transformer. In this Table A.1 there is a description of the contents of the kit and Table A.2 indicates the mixture ratios that should be used to achieve an optimum finish.

ITEM QUANTITY DESCRIPTION

1 1 Lt. Organic zinc epoxy - polyamide primer paint. 2 1 Lt. Polyurethane or vinyl based finish paint. 3 0.25 Lt. Catalyst. 4 2 pieces 2 inch brush 5 1 roll Masking Tape 6 ¼ Lb Cleaning rags. 7 1 sheet Medium sand paper 8 1 sheet Fine sand paper

Table A.1 - Touch-Up Kit Contents

A.1.1 - Surface Preparation Remove all loose paint, oxidation, dirt, burrs and road oil and then sand area with sand paper supplied. Remove all dust and apply a coat of primer. After one hour of curing time apply a finish coat.

A.1.2 - Primer Coat

Thoroughly mix PART-A with PART-C in the proportion stated in Table A.2. Apply the Touch-up Paint Mixture and let dry for 30-60 minutes for proper adhesion and coverage quality. To achieve proper viscosity and ease of application, the pre-mixed primer paint may be thinned with a high quality thinner for zinc epoxy-polyamide paint or employ the thinner indicated in Table A.2. NOTE: Thinner and solvents are not included in the touch-up kit due to their volatile hazardous nature

A.1.3 - Finish Coat

Thoroughly mix PART-B with PART-C in the proportion stated in Table A.2 Apply the Touch-up Paint Mixture and let dry for 30-60 minutes for proper adhesion and coverage quality. To achieve proper viscosity and ease of application the pre-mixed finish may be thinned with a high quality thinner for polyurethane based paint or employ the thinner indicated in Table A.2.

NOTE: Mixed paints with catalyst have a limited shelf life of less than 24 hours. Therefore, it is suggested to mix only what is required for touch-up after the surface preparation is complete.

PYROLAC PRODUCTS DESCRIPTION

C.F.E. - P99 BROWN

15521 BROWN

65990 ANSI 70

15124 IVORY

PART A PRIMER 75090 – C 80% PART B FINISH 80% 75% 80% PART C CATALYZER 65010 – C 20% 20% 25% 20% THINNER MT – 571 20% - 30% THINNER MT – 170 20% - 30% THINNER MT – 381 EQUAL VOLUME EQUAL VOLUME

Table A.2 - Paint mixture preparation table.

When used, thinners are added after the paint and catalyst are mixed. They are mixed as a percentage of total volume or an equal amount to total volume.



IOMM-ENG of 114



Dew Point Analysis & Graphics A.2 - Dew Point Measurements

A Dew Point Measurement can detect the presence of moisture on the insulation package that may have entered the transformer during transit, storage or assembly.

Dew point is important because it is related directly to the partial pressure of water vapor that in turn can be used to determine the percentage of water content in the insulation package.

A.2.1 - Dew Point and Percent of Moisture Content

A.2.1.1 - Establish a gas connection between the Dew Point Measurement device and the pressurized internal transformer environment.

A.2.1.2 - Satisfy the following requirements for accuracy:

2.(1) Transformer has been leak free since factory shipment. 2.(2) The temperature of the internal insulation is known. 2.(3) Transformer internal pressure is known. 2.(4) Twenty-four hours has elapsed since dry gas was added to the tank.

A.2.1.3 - Bleed off tank to dew point device tubing for approximately 5 minutes at the device

connection. A.2.1.4 - Purge device of any atmospheric air. A.2.1.5 - Follow dew point device instructions A.2.1.6 - Read dew point and record. A.2.1.7 - Refer to Chart A.1 - Dew Point to Vapor Pressure Conversion Chart A.2.1.8 - Locate recorded dew point on vertical axis. A.2.1.9 - Trace horizontally across to the internal transformer pressure of zero. A.2.1.10 - From this point drop vertically to obtain an un-corrected vapor pressure value. A.2.1.11 - Read and record tank internal pressure. A.2.1.12 - This vapor pressure must be corrected using the following equation:

)(* HgunitsPPPPP VA

TAVC µ→

+=

Where: • PVC = Corrected Vapor Pressure in µHg • PA = Atmospheric Pressure in psi • PT = Transformer Tank Pressure in psi • PV = Dew Point Vapor Pressure in µHg (from A.2.1.7 - )

A.2.1.13 - Measure and record insulation package temperature. The temperature of the core and coil assembly may be determined by reading the temperature of the gas inside the transformer from the dew point measurement device. As an alternative, this temperature may be obtained by placing a ball of putty at or on the base of the transformer (make sure the putty does not have an evaporating agent). Then, insert a thermometer into the putty touching the transformer steel. The thermometer can also be taped to the base of the transformer. Preferably, perform this step early in the morning when the entire transformer package temperature is in equilibrium. Record temperature in Celsius degrees.

A.2.1.14 - Go to Chart A.2 - Moisture Equilibrium Chart, Moisture Equilibrium Chart. A.2.1.15 - Find on Chart A.2 - Moisture Equilibrium Chart, left vertical axis, mark Vapor Pressure from

step A.2.1.12 - .



IOMM-ENG of 114



A.2.1.16 - Find on Chart A.2 - Moisture Equilibrium Chart, horizontal axis, Insulation Temperature step A.2.1.13 - .

A.2.1.17 - Locate the intersection of these two points on the graph. A.2.1.18 - After finding the intersection point; draw a diagonal line down (staying parallel to

established diagonal lines) to the right hand axis. A.2.1.19 - The intersection of this diagonal line and the right axis is the percent of moisture contained

in the transformer. A.2.1.20 - A value of 0.5% is the upper limit of what is considered normal. A.2.1.21 - Anything above 0.5% moisture content dictates a drying process is required.



IOMM-ENG of 114



Chart A.1 - Dew Point to Vapor Pressure Conversion Chart



IOMM-ENG of 114



Chart A.2 - Moisture Equilibrium Chart



IOMM-ENG of 114



A.2.2 - Moisture Equilibrium

A.2.2.1 - Customer Results Cautions

1.(1) For accurate results the Insulation Temperature must be known exactly. 1.(2) The accuracy of the readings is much more affected during cold weather than during

warm weather seasons. 1.(3) Many parameters affect the dew point measurement. All can and will affect the

accuracy of the measuring process. 1.(4) Parameters affecting results are as follows:

(a) Permeability of gas hose. (b) Condition of gas hose. (c) Proper purging of hose and dew point device. (d) Exact insulation temperature. (e) Dew point device operator skill. (f) Type of dew point device. (g) Skill of accurate chart use. (h) Precision of pressure indicating device or gage.



IOMM-ENG of 114



Insulation Dry-Out Process According to IEEE Std. C57.93.1995 – Guide for Installation of Liquid Immersed Power Transformers, there are mainly four methods that may be used to dry the insulation in case the moisture content is beyond the acceptable value. In this section a brief description of two if them is given to inform the customer about the different choices available to achieve the required insulation dryness. However it is recommended that the user interested in having more information and detail on this matter; consult IEEE Std. C57.93.1995. A.3 - Disclaimer

Even though all the methods described in this section are industry-wide recognized methods; their inclusion in this manual is for informational purposes only. It is the sole responsibility of the customer to choose the method most suitable to their particular environmental conditions or equipment availability. GE-PROLEC will not be held liable for any damage or injury that the use of any of these methods may cause.

A.4 - Circulating Hot Oil Method

This method requires the use of a suitable oil filter plus an oil heater. The heater must be capable of rising and maintaining a top oil temperature of approximately 85°C as the oil is circulated in the transformer tank until the insulation is dry. As the oil circulates through the core and coil, it picks up the moisture contained in the insulation and takes it to the processing equipment, where the moisture is removed from the oil. Any steps taken to maintain hot oil the temperature in the transformer will result in a much quicker moisture removal process. Where possible, it is recommended to insulate the tank and piping of the transformer and keep the radiator or cooler valves closed. The effectiveness of this method will depend upon the water removal capabilities of the filter system, either if a blotter-press filter or a vacuum-drier filter is used. Sometimes, this method is used as a preparation process. When the oil filling process is to be performed under cold weather conditions (less than 10°C ambient temperature), Hot Oil Recirculation may be used to heat the core and coils before starting a vacuum drying process.

Table A. 3 Typical hot oil process under cold ambient temperature conditions (notice the insulating tarpaulins).



IOMM-ENG of 114



A.5 - High Vacuum Method

This is probably one of the most commonly used methods to dry a transformer. It requires a vacuum pump capable of pumping down to an absolute pressure of 0.05 mmHg or 50 µHg and an optional refrigerated vapor trap to collect the water. After the tank has being completely sealed, a vacuum hose should be connected to the transformer. Either a specially designated valve or the flange for the mechanical pressure relief device is generally used for this purpose. The extraction of moisture begins as soon as the residual vapor pressure in the tank is reduced below the vapor pressure of the water in the insulation. The temperature of the insulation system must be above zero degrees centigrade. The dry out will be much faster if the insulation temperature is 85°C. The vacuum should be maintained as long as water is being removed from the transformer. Each manufacturer establishes a series of guidelines to use as reference for the duration of this process.



IOMM-ENG of 114



Winding Resistance and Insulation Power Factor Correction Tables

Winding Power Factor Correction Table

Correction Factor for Winding Power Factor Insulation Insulation Insulation Insulation Insulation Insulation Insulation Insulation Insulation Insulation

Temperature P.F. Temperature P.F. Temperature P.F. Temperature P.F. Temperature P.F. (°C) Correction (°C) Correction (°C) Correction (°C) Correction (°C) Correction

Factor Factor Factor Factor Factor 0 1.56 10 1.38 20 1.00 30 0.63 40 0.42 1 1.54 11 1.35 21 0.96 31 0.60 41 0.40 2 1.52 12 1.31 22 0.91 32 0.58 42 0.38 3 1.50 13 1.27 23 0.87 33 0.56 43 0.37 4 1.48 14 1.24 24 0.83 34 0.53 44 0.36 5 1.46 15 1.20 25 0.79 35 0.51 45 0.34 6 1.45 16 1.16 26 0.76 36 0.49 46 0.33 7 1.44 17 1.12 27 0.73 37 0.47 47 0.31 8 1.43 18 1.08 28 0.70 38 0.45 48 0.30 9 1.41 19 1.04 29 0.67 39 0.44 49 0.29 50 0.28

Insulation Resistance Correction Table

Correction Factor for Insulation Resistance (MEGGER)

Insulation Insulation Insulation Insulation Insulation Insulation Insulation Insulation Insulation InsulationTemperature Resistance Temperature Resistance Temperature Resistance Temperature Resistance Temperature Resistance

(°C) Correction (°C) Correction (°C) Correction (°C) Correction (°C) Correction Factor Factor Factor Factor Factor

0 0.25 10 0.50 20 1.00 30 1.98 40 3.95 1 0.27 11 0.54 21 1.08 31 2.14 41 4.28 2 0.29 12 0.58 22 1.16 32 2.30 42 4.61 3 0.31 13 0.63 23 1.24 33 2.47 43 4.94 4 0.33 14 0.67 24 1.32 34 2.63 44 5.27 5 0.36 15 0.74 25 1.42 35 2.83 45 5.66 6 0.38 16 0.76 26 1.51 36 3.03 46 6.05 7 0.41 17 0.82 27 1.63 37 3.26 47 6.50 8 0.44 18 0.88 28 1.74 38 3.49 48 6.95 9 0.47 19 0.94 29 1.86 39 3.72 49 7.39 50 7.83



IOMM-ENG of 114



Insulation Resistance Correction Worksheet Two Winding Transformer

MEGGER BETWEEN

RESISTANCE MEASUREMENT

INSULATION TEMPERATURE

X CORRECTION FACTOR

= CORRECTED RESISTANCE

1. HV to LV&GRD ______________ MΩ _____________ °C X ____________ ___________ MΩ

2. LV to HV&GRD ______________ MΩ _____________ °C X ____________ = ___________ MΩ 3. HV&LV to GRD ______________ MΩ _____________ °C X ____________ = ___________ MΩ Three Winding Transformer

MEGGER BETWEEN



X CORRECTION FACTOR


1. HV to LV, TV & GRD

______________ MΩ _____________ °C X ____________ ___________ MΩ

2. LV to HV, TV & GRD

______________ MΩ _____________ °C X ____________ = ___________ MΩ

3. TV to HV, LV & GRD

______________ MΩ _____________ °C X ____________ = ___________ MΩ

4. HV, LV & TV to GRD

______________ MΩ _____________ °c X ____________ = ___________ MΩ

Auto Transformer With Tertiary Winding

MEGGER BETWEEN



____________

X CORRECTION FACTOR


______________ MΩ _____________ °C X ____________ ___________ MΩ

______________ MΩ _____________ °C X = ___________ MΩ

1. HV & LV to TV & GRD

2. TV to HV, LV & GRD

Auto Transformer Without Tertiary Winding

MEGGER CORRECTED RESISTANCE

MΩ

BETWEEN RESISTANCE

MEASUREMENT INSULATION

TEMPERATURE X CORRECTION

FACTOR =

______________ _____________ °C X ____________ ___________ MΩ 1. HV & LV to GRD



IOMM-ENG of 114



Damage Claim Form Carrier Notice

Carrier:

Date:

Equipment:

Rating (MVA):

Serial Number: Bill of Lading Number:

Customer Purchase Order Number:

Date Shipped:

Location of Inspection:

Date Received:

Impact Recorder Number:

Railcar Number:

Brief Description of Damage:

(YES) (NO) Suspected Hidden Damage?

The intention of this document is to inform the intention to file a damage claim based on the rough handling evidence provided by the impact recorder(s).

CARRIER AGENT:

GE-PROLEC Service Engineer

Date (mm/dd/yy) Date (mm/dd/yy)

Customer Representative



IOMM-ENG of 114



Quick Decision Continuous Capacity Chart

CLASS OF COOLING

LOSS CONDITION

CONTINUOUS CAPACITY

ONAN 1 or more radiators Use formula 1 ONAN-ONAF 1 or more fans Use formula 2 ONAN-ONAF Loss of all fans Use ONAN rating

ONAN-ONAF-ONAF 1 or more fans Use formula 2 ONAN-ONAF-ONAF Loss of 1 bank of fans Use ONAN-ONAF Rating ONAN-ONAF-ONAF Loss of 2 banks of fans Use ONAN rating ONAN-ONAF-OFAF Loss of pump Use ONAN-ONAF-ONAF rating ONAN-ONAF-OFAF Loss of 1 or more fans Use formula 2 ONAN-ONAF-OFAF Loss of 1 bank of fans Use ONAN-ONAF rating ONAN-ONAF-OFAF Loss of 2 banks of fans Use ONAN rating OFAF Continuous Loss of 1 or more fans Use formula 1

Take steps to shut-down transformer OFAF Continuous Total of loss of cooling package ONAN - Oil filled radiator convection cooling

Oil filled radiator convection

* Cooling with forced oil pump

A.6 - Percent of Continuous Capacity (%CC) Formulas

In case of loss of a heat exchange component (radiator).

ONAF - Oil filled radiator convection cooling with forced air fans

OFAF - * Cooling with forced air fans

Formula 1

100**

11%

+

−=RNRCC η

N = Total number of radiators η = Radiators out of service

esNoLoadLossLoadLosses

R urrentFullRatedC=

Formula 2 In case of loss of a forced air element (fan)

100**

11%

−

−=RN

RCC η

N = Total number of fans η = Fans out of service

ONAN

ONAF

LoadLossesLoadLosses

R =



IOMM-ENG of 114



Oil Properties Guideline Table Oil properties

Years of operation Maximum Number of Neutralization (NN)

Minimum Tension Interfacial (TIF)

0.05 mgKOH/g 35 dynes/cm 5 - 10 years 0.06-0.1 mgKOH/g 30-35 dynes/cm + 10 years 0.1 mgKOH/g <30 dynes/

1 - 5 years

cm

Recommended Tests and Reference Values for Transformer Mineral Oil (*) New transformers prior to energization Suggested limits for continued

use of service-aged oil Test and Method ≤ 69 kV 345 kV and

above > 69 - < 230

kV ≥ 230 - < 345 kV ≤ 69 kV > 69 - < 230

kV 230 kV and

above

25 32 35 28 Dielectric strength ASTM D1816-97, KV minimum 2 mm

gap 52 60 45 55 40 47 50 Neutralization number (acidity), ASTM D974-02, mg KOH/g maximum

0.015 0.015 0.20 0.10 0.015 0.015 0.15

Interfacial tension, ASTM D971-99a, mN/m minimum

1.0 Water content ASTM D1533-00 mg/kg maximum 20 10 10 10 Refer to “Suggested maximum water

content” table. Visual examination, ASTM D1524-94 (1999)

Bright and clear

Bright and clear

Bright and clear

Bright and clear

25°C 0.05 0.05 0.05 0.05 0.5 0.5 0.5 Power factor, ASTM D924-99e1, % maximum 0.30 5.0 5.0 100°C 0.40 0.40 0.30 5.0

1 mm gap 30 23 30

38 38 38 38 25 30 32 Color ASTM D1500-98 ASTM units maximum 1.0 1.0 0.5

* For more information, please consult IEEE Std C57.106-2002

Suggested maximum water contents in mg/kg (or ppm) and percent saturation (*) Average oil

temperature 50°C 60°C 70°C System voltage r ppm)

mg/kg (or ppm) % saturation mg/kg (or ppm) % saturation mg/kg (o % saturation ≤ 69 kV 27 15 15 35 55 15

> 69 kV - < 230 kV 12 8 30 8 20 8 230 kV and greater 10 5 12 5 5 15

* For more information, please consult IEEE Std C57.106-2002



IOMM-ENG of 114



General Maximum Torque Values Table

SAE Grade 5 A-304 Stainless Steel Bolt Size Threads per inch [kg. cm.] [kg. cm.] [ft. lb.] [ft. lb.]

¼” [6.35 mm] 20 110 8 70 5 5/16” [7.93 mm] 18 205 15 140 10

3/8” [9.52 mm] 16 345 25 205 15 ½” [12.7 mm] 13 620 45 415 30 5/8” [15.8 mm] 11 1310 95 900 65

¾” [19.05 mm] 10 1660 120 1100 80 1” [25.4 mm] 8 2070 150 1380 100

2900 1935 140 3595 2420 175

1 ¼” [31.8 mm] 7 210 1 ½” [38.1 mm] 6 260

• The stainless steel bolts used at GE-Prolec are 304 and the nuts are 316.

Notes:

• This table is for steel plate to steel plate application. Do not use it for bushing installation. • When GE-Prolec employs stainless steel fasteners for external transformer application, the

customer is advised to use an anti-seize lubricant on the threads of these fasteners during assembly.

• As a standard GE-Prolec employs stainless steel for all stud applications in combination with zinc electroplated fasteners. Nut, washer, bolt combinations are zinc electroplated with an aluminum Teflon ™ coating to eliminate all fastener lock up and extended life characteristics.

• When thread lubricant is used for assembly, the amount of torque to achieve the same effect is about 70 to 75% of the torque value specified in the previous table.



IOMM-ENG of 114



Specific Component Torque Value Table Oil sealing fasteners Gaskets are installed in retaining grooves. A proper seal will be achieved when the mating flanges are flush with each other. Additional torque will not improve the seal. Tightening the fasteners in an “X” pattern to the list values will provide oil and air seal. If the flanges cannot be pulled flush, the device should be removed and the surfaces examined to determine the cause; misaligned or entrapped gasket, foreign material, damage, etc. Internal fasteners Electrical connections between the internal flex/cables require that the mating surfaces be flush and in full contact. The ½” fasteners should be tightened to 50 ft-lb and 5/8” fasteners should be tightened to 70 ft-lb of torque. After tightening, the contact surface verified. The “back-up” nut should have 25 ft-lb. of torque. (Assure that the flex blade has been assembled to the machined side of the bushing connector.) Should a conflict between bushing OEM brochure recommendation occur for proper torque application, please follow bushing manufacturer guideline.

Torque value Component Bolt / thread size

Threads per inch [kg. cm.] [ft. Lb.]

Radiators. ¾” [19.05 mm] 10 1382 100 Radiator valves. ¾” [19.05 mm] 10 1106 80 Radiator top and bottom plugs 1” [25.4 mm] 8 760 55 Manhole covers ½” [12.7 mm] 13 719 52 Sudden pressure Relay ½” [12.7 mm] 13 304 22

13 304 22 5/8” [15.8 mm] 11 622 45

¾” [19.05 mm] 10 954 69 8 2074 150 16 15

½” [12.7 mm] 13 276 20 5/8” [15.8 mm] 11 346 25

¾” [19.05 mm] 10 415 30 Bushings w/porcelain flange

1” [25.4 mm] 8 484 35 1 1/8 “ [ ‘---- 484 35 Bushings terminal cap 1 ½ “ [ ‘---- 1382 100

Bushing Turrets (CT Adapter) ½” [12.7 mm] 13 622 45 Surge Arresters (Tranquel) ½” [12.7 mm] 13 304 22

16 21 Buchholz/Gas Relay Piping 5/8” [15.8 mm] 11 1437 104 Conservator Piping ½” [12.7 mm] 13 719 52 Flux Shunt ½” [12.7 mm] 13 774 56

½” [12.7 mm] 13 69 5 5/8” [15.8 mm] 11 124

¾” [19.05 mm]½” [12.7 mm] NPT 14 249 18 Temperature indicator 3/8” [9.52 mm] NPT 18 152 11

½” [12.7 mm]Bushing w/metal flange. (i.e. ABB type “O + C”)

1” [25.4 mm]3/8” [9.52 mm] 207

3/8” [9.52 mm] 290

9 Nylon Type 66 Internal Fasteners 10 235 17



IOMM-ENG of 114



Oil Filled Bushing Reservoir



IOMM-ENG of 114



Current Transformers

Receiving, Handling and Storage

Secondary leads from CT’s are brought out of the transformer through a low voltage CT outlet die-cast box that is located on the cover or sidewall of the transformer. The transformer nameplate lists the turn ratios for the various taps of each CT.

Introduction Current transformers (CTs) are installed in power transformers as a source of current for relaying and metering purposes and in connection with winding temperature devices and line-drop compensators. CT’s will safely carry a continuous current and a momentary over load equal to that of the equipment in which they were originally furnished. CT’s have output currents proportional to their primary currents and are designed with varying degrees of accuracy, depending on the application. When furnished for a particular purpose a CT should not be used in any other application without checking its characteristics. Refer to (IEEE C57.13 Standard Requirement for Instrument Transformers) for accuracy classes of relaying and metering CT’s.

Current transformers are normally shipped installed, completely assembled and ready for service except when ordered as renewal or spare parts. CT’s mounted in removable bushing turrets are left in the turret when it is removed for shipment and are to be installed with the adapter turret as an assembly. When ordered as renewal parts, carefully disassemble the CT shipping crate to avoid winding damage. Always lay the CT flat during handling or storage and store in a dry protected area. Description

Two types of CT’s are used in power transformers, the bushing type and the cable or bus bar type. The bushing type consists of a ribbon-wound core of high permeability, low loss silicon steel on which a coil is wound. When the transformer bushing is installed through the CT, the CT serves as a secondary and the bushing as a one-turn primary winding. The manufacture of a cable or bus bar CT is identical to a bushing type, except it has a smaller internal diameter for the primary. They are installed internal on the main winding superstructure and use a cable or copper bus bar as their primary. Cable is used for looping through the CT if more than a one-turn primary is required. Current transformer when applied to bushing and cable or bus bar CT’s refers only to the core and its secondary winding. The CT in itself does not provide adequate insulation for full circuit voltage between primary and secondary and therefore depends on the bushing, cable, bus bar, or other material for this insulation. Secondary windings are of the distributed type, with turns equally spaced around the circumference of the CT core. This distribution gives the CT a low leakage reactance, thus maintaining a high degree of accuracy when the transformer is subjected to over load currents. This winding may be tapped to obtain multi-ratio characteristics when required. The relative instantaneous directions of primary and secondary currents are subtractive as shown in view drawing. The H1 mark on the secondary coil indicates the polarity of the primary conductor with reference to the secondary terminal. When current in the primary conductor flows toward the H1 side of the CT, current in the secondary coil flows out from the terminal X1. With any combination of taps, the tap numerically nearest terminal X1 has the same polarity as X1. CT Outlet

Insulation Resistance Checking the current transformer for accidental grounding or low leakage resistance may be performed with either a 500 or 1000 volt “Megger”. Short circuit the secondary windings, disconnect all external leads from the terminal boards, and Megger the resistance between the secondary winding and station ground. This resistance should have a value in



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mega ohms. If the resistance is unusually low, the transformer and secondary leads should be inspected for accidental grounding. Maintenance CT’s rarely will require attention other than occasional inspection to see that all connections are clean and tight and that the leads have not been damaged. However, if it is necessary to perform an excitation, ratio, ratio and phase angle or insulation resistance test while primary current is flowing in a CT, it is vital that great care is taken in changing burdens or taps to assure that the secondary is not accidentally open-circuited.

CAUTION: The secondary circuit of an energized CT MUST NOT be opened at any time. It must be burdened with a load or short-circuited with a screw at the terminal connection block. If the secondary is opened with current flowing in the primary, an excessive peak voltage of many thousands of volts will develop in the secondary that will cause a hazard to personnel and can magnetize the core and possibly damage insulation.

Connections

Installation CT’s shipped apart from the transformer should have their condition checked before installing. Should moisture have entered during transit or storage it is important that the CT be dried in an oven for 24 hours at a temperature no greater than 90ºC.

Testing When testing is required, the following recommendations are useful.

Excitation Test CT excitation characteristics can be checked, whether in or out of the transformer, by injecting a current of the correct frequency through the primary or secondary of the CT. When current is applied to the primary the induced voltage can be measured across any two secondary leads. Refer to the following circuit drawing:

EDP2XVOLTMETER

DIAGRAM 1

When energized through the secondary the CT acts like an ideal auto transformer, meaning the current can be injected into and the voltage measured from any combination of taps. Refer to the following circuit drawing:



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EDP2XVOLTMETER

IP3AMMETER

VARRES.

AC

DIAGRAM 2

This test is an open-circuit test and must be performed without any load except the averaging voltmeter connected to the current transformer. An averaging or rectifier voltmeter as the DP-2X (a dic. relay with a rectifier calibrated in terms of RMS sine wave voltage) is suggested so results obtained will be independent of the harmonics in the applied current or those developed by the CT. The results obtained may be reduced to a common basis or number of secondary turns because both the ampere turns and the volts per turn are constant for any single value of excitation. When performing this test first demagnetize the core. This is done automatically by checking the excitation at the saturation voltage first and then reducing the current slowly to check the next point without interrupting the circuit and continuing until the lowest point desired has been taken. Note that the power transformer must be de-energized since the excitation current must be under control. The exciting currents obtained from this test should be within 35 to 50 % of the values on the curve (available on request or included with the drawings). If the excitation current is a lot greater than indicated it may indicate that a shorted turn exists which could affect the CT ratio. Ratio (Relay CT) To make a ratio test with a specific load pass a primary current through a bushing, cable or bus bar as the following circuit diagram shows:

P3AMMETERE

RELAYLOAD

DIAGRAM 3 Or inject a voltage to the secondary with the primary open circuited as follows:



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Ip/ N P3AMMETER

VARRES.

1

ACSOURCE

2

Rw

IsP3AMMETER

NORMALLOAD

DIAGRAM 4

If the normal load is small in magnitude connect a resistance, Rw (equal to the resistance between points 1 and 2 through the transformer), in series with the load. The ratio correction factor at the secondary current (Is) will be equal to the quotient of the two meter readings. (RCF=(Ip/N)1/Is). The error introduced by this method with minimal with the resistor (Rw) in the circuit. De-magnetize the core before testing is started.

De-magnetizing CT cores may acquire a residual magnetism which is not erased by load currents. This magnetism may have been produced by energizing the primary with the secondary open circuited or by high over currents. This can occur when a circuit breaker interrupts a high instantaneous current. This will change the density at which the core operates, increasing exciting current and affecting the accuracy of the CT. This error in accuracy although small should be removed by demagnetizing the core. Raise the flux density to the saturation level and then gradually reduce it. Excitation may be obtained with the transformer energized or de-energized. To demagnetize a core while the power transformer is energized use the following:

RELAYLOAD

IP3AMMETER

VARIABLERESISTER

DIAGRAM 5 The resistance should be increased from zero to a magnitude that the ammeter reading will decrease to at least one-half of its original value. Then gradually reduce the resistance to zero and repeat the process several times. To determine the magnitude of the resistance needed, obtain the CT saturation voltage from the excitation curve and divide



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this amount by one-half of the recorded secondary current. This quotient can then be adjusted to the tap being used. Therefore, if the saturation level for a CT is 100 volts on a given tap and the recorded secondary current is 5 amps, the required resistance would be 100/2.5 or 40 ohms. To de-magnetize the CT core with the power transformer de-energized, refer to the excitation curve and determine the amount of secondary current required to saturate the core. Be aware of the turns ratio and tap being used, gradually apply saturation current to either the primary or secondary with the other winding open-circuited. Use diagrams 1 or 2. Then slowly reduce the current to zero. Repeat the process several times.

View of a typical Current Transformer



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Quick Reference of Useful Standards and Guides

Number

Description

IEEE Std C57.12.00-2000 IEEE Standard General Requirements for Liquid-Immersed Distribution, Power, and Regulating Transformers

IEEE Std C57.12.80™-2002 IEEE Standard Terminology for Power and Distribution Transformers

IEEE Std C57.12.90-1999 IEEE Standard Test Code for Liquid-Immersed Distribution, Power, and Regulating Transformers

IEEE Std C57.91-1995 IEEE Guide for Loading Mineral-Oil-Immersed Transformers

IEEE Std C57.93-1995 IEEE Guide for Installation of Liquid-Immersed Power Transformers

IEEE Std C57.104-1991 IEEE Guide for the Interpretation of Gases Generated in Oil-Immersed Transformers

IEEE Std C57.106™-2002 IEEE Guide for Acceptance and Maintenance of Insulating Oil in Equipment

IEEE C57.115-1991 IEEE Guide for Loading Mineral-Oil-Immersed Power Transformers Rated in Excess of 100 MVA (65 °C Winding Rise)

IEEE C57.116-1989 IEEE Guide for Transformers Directly Connected to Generators

IEEE Std 62-1995 IEEE Guide for Diagnostic Field Testing of Electric Power Apparatus – Part 1: Oil Filled Power Transformers, Regulators and Reactors



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Troubleshooting Table

PROBLEM POSSIBLE CAUSE CORRECTIVE ACTION Contaminated core ground bushing. Wipe with a clean damp rag. Dry

thoroughly. Ground strap touching bushing mounting stud.

Be sure ground strap is free of any contact with metal, except for the bushing connection.

All or part of radiator valves not opened. Open all valves. Pump valves not opened. Open valves and verify the proper

operation of the flow gage. Blown radiator fan fuse or tripped breaker.

Replace fuse or reset breaker.

Debris in radiator fins Remove debris

Fan blade shipping plastic ties not removed.

Unplug all radiator fans and replace fuse or reset breaker. Isolate defective fan and reconnect the rest. Replace defective fan. Remove plastic ties.

Radiators out of factory assembly position.

Check upper match marks and re-position the radiator.

Loose valve stem packing nut. Tighten valve stem packing nut. Radiator installed with shipping gasket.

No Teflon tape applied before installation. Valve not closed.

Close valve completely. Remove plug (use an oil dripping pan). Apply Teflon tape to plug and reinstall.

Match mark system inadvertently overlooked during installation

All components are match marked to their transformer position. Remember upper manifolds the valves point up. Lower manifolds the valves point down. The upper manifolds bear the radiators position match mark system. Adhere to match marks and install.

Liquid level gages for load tap changer and main tank switched.

Install liquid level gages in their proper location.

Possible over torque or environmental contamination.

Saturate with an anti-seize liquid or heat nut to expand it and remove. Reinstall using an anti-seize lubricant. Break partial vacuum using dry air.

Load tap changer conservator installed first.

Remove LTC conservator and install pressure relief device.

1. Low core ground megger reading.

2. Zero core ground megger reading.

3. Transformer high temperature.

4. Blown radiator fan fuse or tripped breaker.

Possible faulty radiator fan.

5. Radiators do not seem to fit.

6. Leaking radiator valve stem. 7. Leaking radiator valve flange. Replace shipping gasket with

supplied final assembly gasket. 8. Leaking drain or fill valve

plugs.

9. Radiators and removable manifolds do not fit

10. Oil level in load tap changer and main tank incorrect.

11. Seized external fasteners.

12. Transformer received with negative pressure or partial vacuum.

Environmental temperature change.

13. Difficulty installing pressure relief device on load tap changer.



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PROBLEM POSSIBLE CAUSE CORRECTIVE ACTION Incorrect thermostat setting. Failed power supply to heating resistance. Heating resistance defective.

Reset thermostat to correct temperature. Locate cause of failure and reset. Replace heating resistance.

Silica gel is saturated with moisture. Remove and replace with dry (blue) silica gel. Reprocess wet (pink) silica gel by placing it in an oven or similar device to remove the moisture.

During assembly match mark system was overlooked.

Check match marks on bus bar links and corresponding tank location. Re-assemble.

Copper is self-protective. Environmental contamination problem.

Clean oxidation and apply an anti-oxidant grease or equivalent.

Proper order of installation not followed.

Subjected to a salt-bearing corrosive environmental

Clean pad, apply an anti-oxidant grease or equivalent

Over torque of mounting bolts. Contact GE PROLEC Service Department for corrective action.

Installation on wrong side of bushing or phase connection incorrect.

Rapid crane movements or installation mishandling.

Clean chip surface and paint with glyptol or equivalent dielectric paint. Note: Some manufacturers have an epoxy repair kit.

Pinched between device and mounting flange

Inadvertent contact by client inspection or assembly crew.

Slight damage is no problem. Hanging tape requires rewrapping and covering it with cotton tape.

14. Condensation in control cabinet.

15. Silica gel canister is pink or very pale yellow

16. Neutral ground bus does not fit.

17. Oxidized neutral ground bus or cable.

18. Difficulty installing radiator. 1. Do not install surge arrestor supports or conservator supports.

2. Install diagonal radiator support rods.

3. Install radiators (attention to match marks)

4. Install upper & lower separator angles.

19. Oxidized tank ground pads.

20. Cracked bushing flange

21. Internal low voltage bushing fasteners do not fit.

Install on proper side of bushing terminal or position to proper phase location

22. Chipped bushing porcelain during installation.

23. Damaged an operational gasket during assembly

Contact District GE Sales representative. In and emergency also contact GE/Prolec Product Service Dept. for immediate assistance.

24. Abraded high voltage draw leads.



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PROBLEM POSSIBLE CAUSE CORRECTIVE ACTION O-rings expand and contract with temperature changes.

Place sufficient petroleum jelly in groove to hold gasket in place for assembly. If the ambient temperature is too low or too high, the O-ring may be placed on a warm or cool room, respectively, to help it reshape to its original size.

The stain may be just remaining oil from the installation process.

Clean the area to be checked. Prepare a solution using baby powder and alcohol. Apply this solution to the area. As the alcohol evaporates, a thin coat of white powder stays in the suspected leaking area. If there is really a leak, the white coat will clearly shot it.

Conservator equipped transformers are zero pressure units. Internal pressure might be building up.

Remove silica gel canister shipping plugs. Assure silica gel conservator valves are open.

Oil leak at loose connection between sampler valve and collection device. System not totally purged during assembly.

Find the oil leak that might be introducing bubbles into the tank and eliminate it. Thoroughly purge gas sampler line of air, bleed all air from accessories; side-mounted rapid pressure rise device, radiators, pumps, bushings, turrets and connecting tubing. De-magnetize current transformer core. After de-magnetizing perform excitation, ratio (relay type CT’s), ratio and phase angle (metering type CT’s) and insulation resistance tests.

Reversed device probe in well connections.

Remove probes and re-install correctly.

Possible grounded current transformer. Open resistance heater circuit.

Check CT for ground and remove. Replace resistance heater device. Verify that the short-circuiting screws from the CT terminal board have been removed. Remove rubber anti-vibration shipping slug. Clear slot.

25. O-ring gasket falls out of groove during assembly.

26. There is an oil stain and an oil leak is suspected.

27. Oil leaks at various flanges.

28. Gas collection devices (Buchholz or Accumulator) frequently fill with gas.

29. Current outputs in doubt as to accuracy in current transformers.

Magnetized core due to open circuit (momentary) of secondary or over load of current transformer.

30. Winding temperature device registers lower than the oil temperature device.

31. Winding temperature gage registers the same as the oil temperature gage.

32. Buchholz relay shows continuous contact continuity.

Rubber slug not removed from actuator rod cap.

33. Oil level gauge fogged sight glass.

Lower front drain slot plugged.



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GE PROLEC makes no representation or warranties express or implied, with respect to any information contained in this Manual of Installation, Operation andMaintenance. Likewise, GE PROLEC shall not assume any responsibility or have any liability resulting from the selection or use of this Manual, by any person. This information does not intend to cover all the details of the equipment nor does it try to provide the procedures for every contingency of installation, operation andmaintenance. Professional expertise is a requirement for every person with the task of handling a power transformer. If you require additional information on any problemor particular subject, please contact GE PROLEC Service Department. Phone: 1-800-437-7653. Fax: x 2011 Rev. 1 –Updated the entire document. December 8th, 2005


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PROBLEM POSSIBLE CAUSE CORRECTIVE ACTION 34. Bushing or surge arrester top

connector fractures in service.

Rigid connection made to rigid bus work. Replace damaged component and reconnect through flex connector.

35. Oil level gauge on oil pump vibrating (not reading full flow) Transformer running hot.

Pump rotating in the wrong direction. Pump valve/s not open.

Reconnect feeding source to reverse motor rotation. Open valve(s).

36. Conservator tank type horizontal bushing has oil seal leak.

Overfilled bushing conservator tank. No room for hot oil expansion.

Drain al but 1/3 of tank and check seals for damage. Repair or replace seals and re-install conservator tank.

37. Flex connector in conservator will not fit between tank and conservator piping.

Conservator tank base not adjusted properly.

Loosen conservator tank base bolts, slide away from main tank, re-tighten bolts and install flex connector.

38. Oil in conservator bladder. Over filled conservator tank, with equalizing valve open. Equalizer valve open and silica gel valve closed.

Drain oil from conservator and bladder refill according to operation manual section.3 Proceed as in step 1, be sure to open silica gel valve and close equalizer valve.

39. Found metallic fine particles in LTC mechanism compartment.

Due to normal wear of contacts and mechanical linkages. Will decrease over time and operation.

Remove debris and place in service.

40. Silica gel canister turning pale yellow or pink at the top of the canister.

Moisture was allowed to enter the conservator bladder during assembly. Possible leak in tubing from the canister to the conservator bladder.

No problem, silica gel will absorb all moisture over time. Find leak and seal.

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