koc-e-004 part 1

KUWAIT OIL COMPANY (KDSDCm)

KOC RECOMMENDED PRACTICE FOR

SELECTION, INSTALLATION AND MAINTENANCE OF ELECTRICAL EQUIPMENT IN HAZARDOUS AREAS ( G E N E W REQUIREMENTS)

DOC NO: KOC-E-004 Part 1

ISSUING AUTHORITY:

STANDARDS DIVISION

KOC RECOMMENDED PRACTICE

DOC. NO. KOC-E-004 Pt. 1

FOR

-

Page 2 of 29 1 REV. 1

SELECTION, INSTALLATION AND MAINTENANCE OF ELECTRICAL EQUIPMENT IN HAZARDOUS AREAS

GENERAL REQUIREMENTS

DOC NO. KOC-E-004 Part 1 Formerly COP-E-00 1 Part 1

TABLE OF CONTENTS

TITLE PAGE #

SCOPE

APPLICATION

TERMINOLOGY

REFERENCE STANDARDS & PUBLICATIONS

ENVIRONMENTAL CONDITIONS

SERVICE CONDITIONS

CLASSIFICATION OF SURFACE TEMPERATURES

EQUIPMENT SELECTION FOR HAZARDOUS AREAS

FACTORS AFFECTING CHOICE OF A WIRING SYSTEM

INSTALLATION REQUIREMENTS

EARTHING AND EARTH FAULT PROTECTION

TERMINAL BOX

ISOLATION

WIRING SYSTEMS

GENERAL INSTALLATION RECOMMENDATIONS

CABLE SYSTEM

INSPECTION AND TESTING

QUALITY ASSURANCE

SUPPLEMENTARY REQUIREMENTS FOR CERTAIN ELECTRICAL EQUIPMENT

WITHDRAWAL OF EQUIPMENT FROM SERVICE

MARKING OF ELECTRICAL EQUIPMENT

TABLE OF CONTENTS

DOC. NO. KOC-E-004 Pt. 1 I Page 4 of 29

TITLE

REV. 1

PAGE #

26 DOCUMENTATION

CLASSIFICATION OF DEGREE OF PROTECTION ENCLOSURES OF ROTATING ELECTRICAL MACHINES (IP CODE)

APPENDIX 1

APPENDIX 2

DOC. NO. KOC-E-004 Pt. 1 I Pane 5 of 29 I REV. 1

1.0 SCOPE

1 .I This recommended practice describes KOC's guidelines for the selection, installation and maintenance of electrical equipment in Hazardous Areas.

1.2 It gives recommendations and necessary precautions to avoid ignition of an explosive atmosphere resulting from electrical arcslsparks, hot surfaces or frictional sparks from electrical equipment and installations.

2.0 APPLICATION

2.1 The purpose of this recommended practice is to;

Provide a brief guidance for the area classifications.

Introduce precautions to be taken to ensure that electrical equipment used under various hazardous classifications are adequate for safe operation.

2.2 This document is issued in the following six parts.

Part 7 Recommended Practice for SeIection, lnstallation and Maintenance of Electnkal Equ@ment in Hazardous Areas: General Requimments.

Part 2 Recommended Practice for Selection, lnstallation and Maintenance of Electrical Equipment in Hazardous Areas: Flameproof Enclosure 'd'.

Part 3 Recommended Practice for Selection, lnstallation and Maintenance of Electrical Equipment in Hazardous Areas: Intrinsic Safety 'i'.

Part 4 Recommended Practice for Selection, lnstallation and Maintenance of Electrical Equipment in Hazardous Areas: Increased safety 'e'.

Part 5 Recommended Practice for Selection, lnstallation and Maintenance of Electrical Equipment in Hazardous Areas: Non-sparking type 'n' equipment.

Part 6 Recommended Practice for Selection, lnstallation and Maintenance of Electrical Equipment in Hazardous Areas: Oil Immersion '0'.

3.0 TERMINOLOGY


3.1 Hazardous Area

Page 6 of 29 REV. 1

A Hazardous Area is the zone in which a flammable atmosphere may be present during normal operation or under abnormal or fault conditions and as such it would require special precautions for construction and use of electrical equipment.

3.2 Non-Hazardous Area

A Non-Hazardous Area is an area not recognized as presenting any particular fire risk nor identified as a zone in which a flammable atmosphere may exist.

3.3 Classification of Hazardous Area

The term "Zone" will be used for hazardous area designations and this terminology has been adopted in this document which is further classified as:-

3.3.1 Zone 0 A zone in which a flammable atmosphere is continuously present or present for long periods.

3.3.2 Zone 1 A zone in which a flammable atmosphere is likely to occur in normal operation.

3.3.3 Zone 2 A zone in which a flammable atmosphere is likely to occur only under abnormal operating conditions.

3.4 Flammable Material

A gas, vapour, liquid, dust or solid that can react continuously with atmospheric oxygen which may sustain fire or explosion initiated by a spark, flame or hot surface. (Refer to KOC-G-002 for details about flammable gases, vapours and liquids, related 'T' class and apparatus sub-groups).

3.5 Ex~losive Gas Air Mixture

A mixture of flammable gas or vapour with air under atmospheric condition that may ignite.

3.6 lanition Temperature

The lowest temperature of a flammable substance, gas or vapour at which ignition occurs under prescribed test conditions.

DOC. NO. KOC-E-004 Pt. 1 I Page 7 of 29 I REV. 1

3.7 Maximum Surface Temperature

The highest temperature attained under operational requirements within the rating and overloads and faulty conditions.

4.0 REFERENCE STANDARDS AND PUBLICATIONS

4.1 In the event of conflict between this document and the StandardslPublications referenced herein, the most stringent requirement shall apply unless otherwise specified.

4.2 Any exceptions or deviations from this document, along with their merits and justifications, shall be brought to the attention of KOC Controlling Department I Standards Division for their review, consideration and amendment (if required) of this Publication.

4.3 A list of StandardslPublications is given below which are associated with this Practice. However, the list does not preclude the use of other technical source of information provided that they do not conflict with the listed StandardsIPublications.

4.4 STANDARDS I PUBLICATIONS

Memorandum. Construction of electrical equipment for protection against electric shock.

BS 4568 Part 1

Specification for steel conduit and fittings with metric threads of IS0 form for electrical installations. (Steel conduit, bends and couplers). BS 4568 Part 2

Specification for steel conduit and fittings with metric threads of IS0 form for electrical installations. (Fittings and components). BS 5345 Part 1

Code of Practice for selection, installation and maintenance of electrical apparatus for use in potentially explosive atmospheres (other than mining applications or explosive processing and manufacture). (General recommendations).

DOC. NO. KOC-E-004 Pt. 1 I Page 8 of 29 REV. 1

BS 5501 Part 1

Electrical apparatus for potentially explosive atmospheres. (General requirements). IEC 34-5

Rotating Electrical Machines Part 5: Classification of degrees of protection provided by enclosures of rotating electrical machines (IP code). IEC 79-0

Electrical apparatus for explosive gas atmospheres. Part 0: General requirements.

KOC G-002

Hazardous Area Classification.

5.0 ENVIRONMENTAL CONDITIONS

5.1 The environment of Kuwait, is severe on all equipment and must be considered carefully before procurement of plant and equipment. It must be assumed that, unless otherwise specified, equipment may be subjected to sand and fine particle dust storms, salt laden winds, chemical contaminants and extreme temperatures.

5.2 Humidity can pose a serious problem with long periods of relative humidity level of 100% being part of the normal weather pattern.

5.3 All electrical components shall be designed for continuous operation under ambient temperature of - 3 ' ~ to + 5 0 ' ~ in the sunshade.

6.0 SERVICE CONDITIONS

6.1 All materials used for electrical installation shall be new and in all respects suitable for continuous operation under the environmental conditions.

6.2 Reliability of all equipment to perform continuously in the service conditions specified is essential. Such reliability of all components shall be substantiated by the same component in operational use elsewhere for a minimum period of 3 years.

6.3 The company attaches a great value to the reliability therefore all constructional material shall be of high quality. Prototype or unproven equipment not having well established record of satisfactory service will not be considered.

CLASSIFICATION OF SURFACE TEMPERATURES


7.1 The highest temperature which is attained in service under the most unfavourable conditions by any part or surface of an electrical apparatus, which may lead to an ignition of surrounding atmosphere.

7.2 The maximum permitted surface temperatures are given below in relation with 'T' class:

Page 9 of 29

7.3 The maximum surface temperature of the electrical equipment shall be below the lowest ignition temperature of the explosive gas atmospheres for which the equipment is designed.

REV. 1

7.4 The equipmentlapparatus shall be clearly marked with the specified permitted ambient temperature.

EQUIPMENT SELECTION FOR HAZARDOUS AREAS

8.1 Only certified and approved electrical equipment shall be permitted in all hazardous areas. Such equipment shall have a type of protection appropriate to the Zone in which it will be operated. The equipment group and temperature class shall also be appropriate to all types of gases and vapours.

8.2 Equipment for use in hazardous areas shall be selected in accordance with the criteria of area and temperature classifications.

8.3 Equipment which is suitable for installation in all hazardous areas shall be certified for use in those areas by a testing authority with an international recognition.

8.4 Electrical equipment including electrically operated process instruments, shall not be installed in a hazardous area when it is practical and economical to site elsewhere.

Where the installation of electrical equipment in hazardous area is unavoidable then a special method of safeguarding must be adopted.


Any unauthorized modifications to equipment or the system will invalidate the certification and render the equipment or system unsuitable for use in a potentially hazardous area.

Certified equipment shall bear the authority's certification No. in addition to all other marking required by the individual Standard.

Page 1 0 of 29

Luminaries, marshalling boxes, junction boxes, remote control stations and socket outlets installed in outdoor location shall be of standard pattern to avoid a multiplicity of different types and shall be appropriate for the hazardous areas in which they are installed.

REV. 1

Equipment installed shall be certified as follows:

In Zone 1 areas: EExd. In Zone 2 areas: EExd, EExe or EExn.

A special protection (specifically certified for use in Zone 0) shall be applicable for any system or apparatus installed in Zone 0.

Light metal and their alloys and other material of oxygen carrier shall not be used in Zone 1 under the risk of frictional contacts.

Portable and transportable equipment with unprotected light metal enclosures shall not be taken into hazardous areas unless suitably protected against frictional sparking.

Standard industrial portable and transportable electrical equipment may be used under the 'KOC permit system' guaranteeing the absence of flammable atmosphere for certain period and location.

Particular attention should be given for protection against weather, ingress of liquids, dust, corrosion, the effects of solvent and heat from adjacent plant.

FACTORS AFFECTING CHOICE OF A WIRING SYSTEM

9.1 Insulating materials may be attacked by certain chemicals and where such contact or exposure is expected a suitable means of protection shall be considered to avoid deterioration.

9.2 Where cables may be subjected to excessive flexing the use of mineral insulated cables should be avoided.

9.3 Where electrolytic corrosion of metal sheath may result from contact with walls or other surfaces to which the cable is attached, it should be kept clear of such services or covered with a protective sheath.

10.0 INSTALLATION REQUIREMENTS


10.1 As a consequence in the nature of environment in hazardous areas it is generally applicable that all type of protections are considered at the design stage of equipment, plant and installation.

10.2 All connections to certified equipment must be made by glands designed to maintain the integrity of the equipment.

Page 1 1 of 29

10.3 It is recommended procedure to ensure that the following conditions are met properly:

REV. 1

ACCESS FOR INSPECTION

Access shall be provided for inspection and maintenance to all equipment, plant and installations.

PLANS AND RECORDS

Cable routing drawings shall be provided and installation 81 certification for the equipment shall be complied with updated hazardous area classification drawings.

ELECTRICAL RATINGS

Electrical equipment and material shall be selected, installed, protected and maintained within the limits of their electrical rating for power, voltage, current, frequency, duty and other characteristics.

INSTALLATION OF EQUIPMENT

Where the equipment is to be installed in areas of high mechanical risk, additional measure such as provision of guards for light transmitting parts may be necessary. However, such additional measures should not impair the integrity of the type of protection. Where it is possible a higher IP code shall be recommended for safeguarding of the equipment, provided it does not cause a higher impact on the cost. The manufacturer shall provide clear installation instructions.

INTEGRITY OF INSULATION

Care should be taken during installation to maintain the degree of electrical insulation provided during the design and manufacture of the equipment so that the possibility of accidental sparking or arcing is avoided.

10.3.6 AUTOMATIC ELECTRICAL PROTECTION


All circuits and equipment in hazardous areas should be provided with means to ensure automatic disconnections in the event of overcurrent, overload, single phasing or earth fault conditions.

REV. 1

The equipment with particular type of protection may have additional andlor alternative requirements for which the reference should be made to the recommendations in the appropriate part of this document.

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11.0 EARTHING AND EARTH FAULT PROTECTION

Earthing of intrinsically safe electrical systems is detailed in part 3.

High voltage systems should have earth fault protection in addition to overcurrent protection. Earthing of power distribution system should be in accordance with appropriate recommendations for the electrical installations but it shall prevent ignition or explosion caused by electric sparks or heat due to earth fault of low and high voltage electrical circuits. The protection against electrical shock shall be in accordance with BS 2754.

The power, lightning and static earthing system, where they exist in the same area, should be effectively connected together to ensure as far as possible that all metal work in a particular area is at the same potential under all conditions.

The earth fault protection of isolated low voltage circuits shall be provided with the sensitive automatically operated earth fault circuit breaker andlor alarming device with suitable protective measures.

The earth fault protection of high voltage circuits shall be provided with automatically operated circuit breaker andlor alarming device which operates immediately when an earth fault occurs.

Protective earthing of all exposed non-current carrying metal parts such as enclosures, ducts and metal tube of cables, housing of electrical equipment, fixed or movable metal conduits and their fittings, metal sheath of cables shall be earthed in conformity with the following:

The earthing resistance of all exposed non-current carrying metal parts shall not be more than 10 ohms for low voltage circuits of upto 300 volts.

I f the isolated circuits are provided with an earth fault protective device or automatically operated earth fault alarming device having a 30 mA sensitivity then the earth resistance can be accepted upto 100 ohms.


The earthing electrodes or rods shall be of copper or copper coated steel which shall not be corroded by salt laden soil, gases, acids etc.. in order to maintain a constant earthing resistance.

REV. 1

The earthing conductors shall be with insulation coverings equivalent to or superior to 600 Volts PVC insulated conductors. The cross section shall be large enough not to attain a hazardous high temperature as a result of maximum anticipated earth fault current.

It is preferable to provide separate earthing conductor in the heavy gauge steel conduits. However, the electrical continuity must be insured throughout the length of conduit. The conduit earthing resistance shall be maintained as low as practicable but in all circumstances it shall not exceed the value stated in clause 11.6 above.

Where the flameproof metal conduits wiring or the heavy gauge steel conduit wiring is installed it shall be of seamless type and the earthing conductor shall be in principle run in the conduit and shall be connected to the earthing terminals within the terminal box.

In multi-core cable wiring the earthing core shall be employed as earthing conductor and shall be connected to the earthing terminal within the terminal box.

The armour of a cable should be selected to be adequate for current carrying capacity for a maximum anticipated earth fault current, it may be used as an earthing conductor provided it is properly connected to the metallic glands and the enclosureslhousingslboxes are adequately earthed. The sheath of a metal sheathed cable should not be used as the neutral conductor.

When the exposed wiring of earthing conductor is unavoidable, precaution shall be taken against mechanical injury and loosening of connecting parts upto the earthing terminal.

When a hand lamp or movable electrical equipment is used, one of the core of flexible cable shall be earthing conductor. The end of earthing conductor shall be connected to the earthing terminal and earthing point in the plug and socket arrangement.

Insulated covering of an earthing conductor shall be in green and yellow stripes or green in colour. I f unavoidable the other colour may be used, provided the terminations of the conductor or core are clearly and permanently labelled with earthing symbollletter or greenlyellow colour sleeving .

12.0 TERMINAL BOX

12.1 Suitably protected terminal boxes should be provided and they shall have been type tested according to Zonal requirements.

12.2 The cable glands of terminal boxes shall be selected to ensure the equipment integrity is maintained.

12.3 The motor terminal boxes shall be capable of withstanding full internal short circuit conditions without danger to the plant or personnel.

12.4 An earthing stud may be specified to be provided within the terminal box in addition to the external earthing terminal.

12.5 The specific installation requirements stated within the equipment certification shall be closely adhered to. This is specifically important with Ex 'e' and Ex 'n' equipment.

13.0 ISOLATION

13.1 As far as practicable the means of isolating electrical supplies to the hazardous areas shall be kept outside the hazardous Zones.

13.2 Where the means of isolation is located inside the hazardous Zones it shall meet the requirement of appropriate type of protection.

13.3 All electrical circuits should be provided with an effective means of complete circuit isolation including neutral conductors. This applies equally to single phase circuits.

13.4 The means of isolation should be capable of being locked in the off position to prevent the restoration of supply to the apparatus whilst the risk of exposing unprotected live conductors to an explosive atmosphere continues.

13.5 Adequate labelling should be provided adjacent to each means of isolation to permit rapid identification of circuit or group of circuits thereby controlled.

13.6 A master isolator may also be provided which will permit quick disconnection of large areas of plant in the event of an emergency.

14.0 WIRING SYSTEMS

14.1 Cable routes shaM be planned wherever possible in conjunction with other major services, pipe tracks, buildings and roadways to provide protection.

14.2 Damaged cable shall not be used in any installation. Any proposed repairs shall be subject to testing and approval by KOC.

DOC. NO. KOC-E-004 Pt. 1 I Page 15 of 29 REV. 1 Where cable joints would be unavoidable they should be encapsulated or made in compound-filled junction box and be protected in accordance with the requirements of Zones.

All equipment, connections and wirings shall be clearly marked for recognition.

Cables shall be direct buried, installed in .structural trenches or run overhead on supports as indicated on the cable routing drawings.

The wiring in hazardous Zones shall be made in such a way that it is protected against mechanical damage. Cables shall be arranged or drawn into screwed, solid or seam welded steel conduits.

Preference must be given to armoured cable which is cheaper and easy to install. Conduits should be kept to a minimum.

Only metallic type conduit shall be used for hazardous areas. Between safe and hazardous areas and between Zones 1 and 2 of hazardous areas, approved type flameproof stopper boxes shall be installed in conduit systems.

For additional requirements for the conduit system that are relevant to particular types of protection, the other parts of this document shall be referred.

Elbows of solid type may be used for the immediate connection of conduit to the equipment.

Surface mounted conduit should be supported by spacing saddles.

All joints in an assembly of conduit should be painted after assembly with moisture resistance paint to inhibit the development of rust.

Attention should be given to the importance of efficient earthing and bonding of all conduit systems.

Screwed steel conduit systems are satisfactory for many applications but it should not be used where vibration may cause fracture or loosening of joints or where excessive stress is expected. In the likelihood of excessive condensation or moisture or corrosion the steel conduit system shall not be used.

Electrical continuity must be ensured between metallic enclosures and conduit, armour, or cable sheaths across any joint in the conduit by the integrity of joint itself. If under certain circumstances the external bonding is necessary then it should be connected directly across the joint.

If flexible metallic tubing is used then fittings should be constructed and assembled in such a manner that damage to the cable is avoided and adequate earthing or bonding should always be maintained.


Where an overhead supply line is used for either power or telecommunicdtion circuits, it shall be terminated to a cable outside the hazardous area to be fitted at or near the terminal pole with effective surge protective technique. The armouring or metal sheathing should be earthed as near as possible t o the earth electrodes of the surge protective equipment. In addition, it shall be bonded effectively to the lightning protective system if associated with the hazardous Zone.

Single core armouring cable shall not be used unless the armouring is non-magnetic.

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Page 16 of 29

The insulation provided by a non-metallic outer sheath of a cable shall usually be sufficient to avoid accidental contact between conduit or metallic armouringlsheathing of cables, pipe work and equipment containing flammable gases, vapour or liquids. Where exposure of this nature is unavoidable, appropriate protective measures should be taken.

REV. 1

Where cables or conduit pass through a floor, wall, partition or ceiling that forms a gas or fire barrier, specially designed barrier plate must be used. Where not possible the holes provided for this purpose should be filled with incombustible material to the full thickness of floor, wall, partition or ceiling. Alternatively, cable glands or cable transits may be used.

Where trunking, ducts, pipes or trenches are used to accommodate cables, precaution should be taken to prevent the passage of flammable gases, vapours or liquids from one area to another. Such precaution may involve the sealing of trunking, ducts and pipes and sand filling of the trenches or the adequate ventilation.

Unused cable entries to the electrical equipment must be closed with plugs suitable for the type of protection according to equipment and Zone.

Where accessories i.e. junction boxes are used for the interconnection of cables it shall be ensured that they are suitable for the particular hazardous Zone.

For terminal connections to fixed equipment that may be required from time to time to be moved for a small distance (i.e. motors on slide rails), a suitable flexible and transportable cable shall be used to permit necessary movement without detrimental effect to the cable.

14.26 Consideration should be given to protect the cables and conduit against fire and fire transmission where high process integrity is required.

15.0 GENERAL INSTALLATION RECOMMENDATIONS

For selection, design, manufacture, testing and supply of electric power cables and wiring, the KOC Standards E-023 shall be referred.

The cable entry to the apparatus should maintain the integrity of the type of protection of the apparatus. Certain types of cable employ materials that can exhibit significant 'cold flow' characteristics which could have adverse effects on the protection of the apparatus. Where such cable is to be used a suitable cable entry device should be employed, e.g. certified glands.

No alterations should be made to any installation without due consideration of the necessity to maintain the integrity and the type of protection involved. Alterations to apparatus or systems may invalidate any certificate or other documentation relating to that apparatus or system.

Where circuits traverse a hazardous Zone in passing from unclassified area to different Zones, the wiring system in the hazardous Zones should be in accordance with the recommendations of this document under appropriate parts.

A wiring system should be installed so that it is prevented being exposed to mechanical damage, corrosive or solvent materials and the effects of heat. Where exposure of this nature is unavoidable, appropriate protective measure should be taken.

16.0 CABLE SYSTEM

16.1 For selection of general cable and installation (KOC Recommended Practice) KOC-E-008 shall be referred.

16.2 The conductors of cable may be of copper or aluminium but plain aluminium should not be used for conductors with cross-sectional area of less than 16 square mm. The use of aluminium conductor in Ex'd flameproof enclosures should be avoided.

16.3 All cables shall be provided with adequate mechanical protection. Rising cables should be clipped, cleated or otherwise attached to suitable support to provide adequate mechanical protection and support.

16.4 Certain types of protection requires specific type of cable glands therefore the reference should be made to relevant part of this document

PAPER INSULATED CABLES

Where paper insulated armoured cables are used and such cable may be exposed to high temperature, preference should be given to non-draining cables. The vertical run of paper insulated cable should be avoided.

Cable boxes i f necessary should be arranged for sealing the cable insulation and should be provided with adequate means of ensuring the earthing continuity of the metallic sheath and/or armour.

MINERAL INSULATED METAL SHEATHED CABLES

Cable fittings should be of a type approved for use with the equipment to which they are to be attached and should be arranged for sealing the cable insulation and be provided with means for ensuring adequate earthing continuity.

Where there is a risk of mineral insulated cables being exposed to excessive inductive voltages, surge suppression should be fitted. Such surge suppression devices installed in hazardous area shall be suitably protected.

Specific types of sealing is required under certain types of protection therefore the reference should be made to the appropriate part of this document.

ALUMINIUM SHEATHED CABLES

Aluminium sheathed cables should be avoided unless they are provided with a robust protective covering. Such cables even protected, should not be used in Zone 0.

Consideration should be given to the avoidance of frictional contact with walls, floors and other surfaces where a risk of mechanical impact is present.

17.0 INSPECTION AND TESTING

17.1 GENERAL

To minimize the risk of ignition by electrical installation & equipment in hazardous areas, an efficient inspection, maintenance and testing of equipment and systems are essential.

DOC. NO. KOC-E-004 Pt. 1 I Page 1 9 of 2 9 REV. 1

It should be noted that correct functional operation does not itself indicate conformity with the recommendations for the safe use of equipment. The general recommendations for inspection, maintenance and testing are further detailed below:

17.2.1 PERSONNEL

The inspection, maintenance, replacement, repair and testing of equipment shall be carried out by competent personnel only. They should have been trained with sufficient instructions for various types of protection. Such personnel shall always be given refresher courses to acquaint them on the latest techniques and developments in the industry. The records of all such training shall be maintained. Their training shall cover the following as minimum:

Personnel shall be trained in the safety related work practices, safety procedures, and other safety requirements.

Personnel shall not be permitted to work in an area where they are likely to encounter electrical hazards unless they have been trained to recognize and avoid the electrical hazards to which they will be exposed.

Personnel shall be safeguarded from injury by appropriate protective equipment while working in situations where there are potential electrical hazards.

Appropriate alerting techniques shall be used to warn and protect personnel from hazards which could cause injury and burns due to electric shock or other failure to the electrical system.

In case of Contractor's worker, the employer shall be responsible for implementation of lockout-tagout procedures. Contractor's employees shall be trained to understand the safety significance of their responsibility in implementing the safety procedures.

The lockout-tagout procedure shall be complied with when the work is performed on or near de-energized circuit or equipment where a power supply could be restored inadvertently.

Personnel who are assigned to work on or near the de- energized circuits or equipment shall understand the purpose of lockout-tagout procedure and its implications to their specific work assignments

17.2.2 ISOLATION OF EQUIPMENT


No apparatus should be opened in hazardous area until it has been disconnected from the source of supply and effective measures are taken to lock the disconnectorslisolators in the open position to avoid the circuit being energized before re-assembly.

REV. I

Where the circuit is protected by fuses, it shall be ensured that removal of fuse will not induce any spark.

Precautions shall be taken where heavy rotating machinery is involved that even after disconnecting the power supply it may produce harmful back e.m.f. at the terminals until it is completely stationary and the power capacitors have been discharged fully.

Where it is essential to restore the power supply for testing purposes before the apparatus is reassembled, a special work permit shall be obtained certifying that the area is free from flammable gas or vapour.

A provision shall be made in the control circuits to trip and lockout the large motors in the event of power supply failure to prevent sudden start-up when the power supply is restored.

The enclosures of electrical components such as capacitors, diodes, transistors which may discharge residual energy and may maintain higher temperature class shall be labelled, stating that "DELAY IS REQUIRED BEFORE ATTEMPTING TO OPEN THE ENCLOSURE".

17.2.3 FIELD REPLACEMENT OF BATTERIES

Batteries should preferably be replaced in unclassified areas. Where it is necessary to replace the batteries in hazardous areas a due care shall be exercised as the batteries with the type of protection "i" may be replaced provided that limiting resistor associated with the battery is not disconnected.

Ignition of an explosion in hazardous areas can start with a cracked or broken flash light bulb that remain glowing. The use of Halogen Krypton or similar high intensity bulb are not permitted to be used on the flashlights.

All electrical equipment, system and installations should be inspected prior to commissioning to confirm that the selection and installation is appropriate in accordance with the recommendations.

17.2.4 FIELD REPAIR AND MAINTENANCE


No repair or maintenance shall be carried out by the use of an open flame or other source of ignition i.e. welding, brazing, grinding, blasting in the hazardous areas until the conditions have been made safe by the control of flammable material and a gas free certificate has been obtained.

Such certificate shall limit the time and location. Adequate measures should be taken for frequently repeated test that the safe conditions are maintained.

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17.2.5 INITIAL AND PERIODIC INSPECTION

REV. 1

The initial inspection shall cover the following as minimum and it shall be recorded:

Equipment appropriate for the area classification

Correct temperature classification

Correct gas groups

Correct circuit identification

Cable entries, barrier plates, stoppers and glands are secured, complete and appropriate to the type of protection

Tightness of electrical connections

Insulation resistance measurement

Correct and continuous rating of equipment and components

Satisfactory earthing, bonding system

Earth electrode resistance measurement

Earth loop impedance measurement

b Operation and setting of protective devices where appropriate

b Any physical damage or alteration to the equipment or wiring systems

b Adequate environmental protection

Flame paths must be examined periodically for signs of corrosion pitting or damage. A feeler gauge must be used to ensure the flame path gap is not excessive.

All cover bolts must be installed and secured.

I f at any time there is a change in the area classification or in the characteristics of flammable material used in the area or i f an equipment is moved from one location to another, an inspection should be made to ensure that the type of protection and temperature class are suitable for the revised conditions.

Any repair, adjustment and modification to any equipment or installation shall not affect the integrity of the equipment.

7.2.10 All equipment, systems and installations shall be inspected regularly and the results of all inspections shall be recorded so that review of inspection frequencies is effective.

DOC. NO. KOC-E-004 Pt, 1

17.2.1 1 Where large number of similar items such as luminaries, junction boxes, etc.. are to be inspected, it may be feasible to carry out inspection on a sample basis provided that the degree of sampling in addition to the inspection frequencies is subjected to review.

17.2.12 Repair contractors must be able to demonstrate their knowledge and ability to maintain equipment integrity. This is particularly important with the motor rewinding companies.

Page 22 of 29

PERIODIC TESTS

REV. 1

1 17.3.1 It is recommended, provided danger is not introduced, the

following checks shall be carried out at intervals of not more than two years.

Insulation Resistance Test.

This test shall be carried out in such a way that safety devices and insulation used in low energy or low voltage equipment and circuits are not subject to damage by excessive voltage.

Earth loop impedance measurement should be carried out at a current of at least 15 A.

(Both the above tests insulation resistance and earth loop impedance shall be carried out when the area concerned has been certified as explosive free atmosphere). Corrosion of enclosures, fixings, cable entries etc.

Loose electrical connections, including those for earthing, bonding, etc.

Loose fixing glands, conduit, stopper, etc.

Condition of enclosures gasket and fastenings.

Leakage of oil or compound.

Inadvertent contact between rotating and fixed parts.

Integrity of guards.

Correct ratings and settings of protective devices

Correct lamp ratings or type.

Undue vibration.

Undue accumulation of dust and dirt.

Unauthorized modifications or adjustments. Damage to the apparatus or wiring system.

Flexible cable and their termination.

Condition of appropriate protective paint or other compound.


17.3.2 Ignoring the above mentioned periodical inspection can affect the deterioration of apparatus or otherwise lead to an unsafe condition.

17.3.3 All parts and installations shall be kept clean and free from accumulation of dust and dirt which may cause excessive rise in the surface temperature thereby invalidating the temperature classification.

Page 23 of 29 REV. 1

DOC. NO. KOC-E-004 Pt. 1 I Page 24 of 29 REV. 1 QUALITY ASSURANCE

The manufacturer shall operate a quality system to ensure that the requirements of this Standard are achieved. The quality system shall be preferably based on IS0 9000. Certification may be done by internationally reputed inspection agencies. Verification of the Vendor's quality system is normally part of the pre- qualification procedure, and is therefore not detailed in the core text of this standard.

SUPPLEMENTARY REQUIREMENTS FOR CERTAIN ELECTRICAL EQUIPMENT

The following equipment shall meet the supplementary requirements of IEC-79-0 Section Three.

Rotating Electrical Machines

Switchgear

Fuses

Plugs and Sockets

Luminaries

Hand Lamps & Cap Lamps

WITHDRAWAL OF EQUIPMENT FROM SERVICE

20.1 Whenever it would be necessary to remove any equipment from service for maintenance or replacement purposes, it shall be ensured that exposed conductors are terminated in an appropriate certified enclosure.

20.2 The cables should be protected by adequately insulating the ends of conductors and isolating the cables from all sources of power supply.

20.3 Where the electrical equipmentlcomponent is permanently withdrawn from service, associated power supply shall be isolated and wiring should be removed or correctly terminated to appropriate certified enclosures.

20.4 Where special tools or fastenings are required to be used it shall be ensured that these are available.

MARKING OF ELECTRICAL EQUIPMENT

21.1 The electrical equipment shall be marked on the main part in a visible place preferably on rating plate. The marking shall be legible and

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durable taking into account possible chemical corrosion.

Marking shall be intended to aid the user in identifying the type of protection for which the equipment is suitable.

The marking shall include:

The name of the manufacturer or registered Trade Mark.

The manufacturer's type of identification.

The symbol 'Ex' which indicates that the electrical apparatus has been constructed and tested for use in an explosive gas atmosphere or specifically associated with such an equipment.

The sign for each protection used shall be as:

'd' - for Flameproof enclosures.

' i ' - for Intrinsic Safety. If it is further categorized it shall show ia or ib accordingly.

'e' - for Increased Safety.

'n' - for Non-sparking equipment.

'0' - for Oil Immersed apparatus.

The temperature class or maximum surface temperature in degree Celsius or both. When the marking include both the temperature class shall be given last in parentheses.

Electrical apparatus having maximum surface temperature greater than 450 "C shall be marked with the temperature only.

Serial number where applicable.

The name of the certifying authority.

The certification reference, the year of certification, followed by the serial number of certificate in that year.

Where different types of protection are used for different part of electrical apparatus, each respective part shall bear the sign for the type of protection concerned.

Where more than one type of protection is used in an electrical apparatus the sign for the main type of protection shall appear first and be followed by the signs for other types of protection.


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21.12 Any other marking normally required by standard of construction of the electrical apparatus.


21.13 Where the mounting of the machine has an influence on the degree of protection, the intended mounting arrangements shall be indicated by the manufacturer on the rating plate or in the installation instructions.

REV. 1

22.0 DOCUMENTATION

22.1 All correspondences, drawings, instructions, data sheets, design calculations, or any other written information shall be in English language.

22.2 All dimensions, units of measurement, physical constants, etc. shall be in SI units, unless otherwise specified.

23.0 CLASSIFICATION OF DEGREE OF PROTECTION FOR ENCLOSURES OF ROTATING ELECTRICAL MACHINES (IP CODE)

The classification which has been accepted internationally for the degree of protection provided by enclosures of rotating electrical machines is designated by the letters IP followed by two characteristics numerals signifying conformity with the conditions.

The first characteristics numeral indicates the degree of protection provided by the enclosures to persons and to the parts of the machine inside the enclosures.

The second characteristics numeral indicates the degree of protection provided by the enclosures with respect to harmful effects due to ingress of water.

When it is required to indicate a degree of protection by only one characteristic numeral, the omitted numeral shall be replaced by the letter X, for example IPX5 or IP2X.

Additional information may be indicated by a supplementary letter following the second characteristic numeral. I f more than one letter is used, the alphabetic sequence shall apply.

The IP enclosure classification may be followed by a letter indicating whether the protection against harmful ingress by water (or liquid) was tested with the machinery, stationary (letter S) or in operation (letter M).

23.7 In the absence of letter S or M indicates that the protection was assessed with the machine both running and stationary.

23.8 When all parts of a machine do not have the same degree of protection, the designation of the lowest degree should be shown first, followed by the other designation with an indication of the part to which it applies.


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DOC. NO. KOC-E-004 Pt. 1 I Page 28 of 29 REV. 1 APPENDIX 1

Degrees of protection indicated by the first characteristic numeral

TABLE I

No protection of persons against contact with live or moving parts inside the enclosures.

No protection of equipment against ingress of solid objects. Protection against accidental or inadvertent contact with live or moving parts inside the enclosures by a large surface of human body such as hand (but no protection against deliberate access). Protection against solid object exceeding 60 mm in diameter.

2 Protection against contact with live or moving parts inside the enclosures by fingers or similar object not exceeding 80 mm in length and 12 mm in diameter.

3 Protection against contact with or approach to live or moving parts inside the enclosures by tools or wires exceeding 2.5 mm in diameter.

I Protection against ingress of small solid objects. I

Protection against contact with live or moving parts inside the enclosures by tools, wires or such objects of thickness greater than 1 mm.

I Protection against ingress of very small solid objects, I foreign bodies. - I

Complete protection against contact with live or moving parts inside the enclosures.

P

Protection against harmful deposits of dust. The ingress of dust is not totally prevented but dust cannot enter in an amount sufficient to interfere with satisfactory operation of the equipment enclosed.

6 Complete protection against contact with live or moving parts inside the enclosures including ingress of dust.

* - When subiected t o the test for characteristics numeral 5.

APPENDIX 2

Degrees o f protection indicated by the second characteristic numeral

TABLE II

0 I No special protection. I


Protection against dripping water (condensed or vertically falling). Drops of condensed or falling water shall have no harmful effect.

i

Page 29 of 29

2 Protection against drops of liquid (condensed or falling) shall have no harmful effect i f the equipment is tilted at any angle upto 15' from its normal vertical position.

REV. 1

Water falling as a spray at an angle upto 60' from vertical shall have no harmful effect.

I Protection against rain storms. I

4 Protection against water splashing against the equipment from any direction shall have no harmful effect.

5 Protection against water jets. Water projected by a nozzle from any direction to the equipment shall have no harmful effect.

6 Protection against water from heavy seas. Water projected in powerful jets shall not enter the equipmentlenclosures.

7 Ingress of water shall not be possible even i f the machinelequipment is immersed in water under stated conditions of pressure and time. Protection of equipmentlmachine against indefinite immersion in water under specified pressure.

I The machine is suitable for continuous submersion in water i.e. machine is hermeticallv sealed. TEST CONDITIONS

For the detail of the test conditions necessary for establishing the degree of protection of an enclosure, and particularly for the conditions appropriate to rotating electrical machine, the appropriate specifications should be consulted.

koc-e-004 part 1

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