training course nx-air intro & safety

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NX-Air_M_P Training Intro Doc Sasol.doc

1006884 - N. Inderbiethen 25.09.2012

First Line Operation & Maintenance – Training Course

Siemens Vacuum Switchgear Type "NX-Air W / M & P"

Index

INTRO An Introduction to Vacuum Technology

A BRIEF INTRODUCTION TO THE SIEMENS VACUUM CIRCUIT BREAKER MANUFACTURING PROCESS AND A TECHNICAL OVERVIEW OF THE ARC PRINCIP LE AND DESIGN PHILOSOPHY BEHIND THE CONCEPT OF "VACUUM ARC INTERRUPTION" AND THE SCIENCE INVOLVED TO ACHIEVE ONE OF THE HIGHEST GRADES OF TRUE "HIGH QUA LITY ELECTRICAL SWITCHING PRODUCTS" AVAILABLE TODAY…

1. Safety Instructions 2. NX-Air W / M & P Switchgear Description

in an introductory slide-show format 3. NX-Air All Types Descriptive Catalogue

4. NX-Air M & P Contactor Panel 5. NX-Air & NX-Air P Circuit Breaker Panel 6. 3AH & K (new) Vacuum Circuit Breakers

7. Vacuum Circuit Breaker Type: 3AH-1 8. Vacuum Circuit Breaker Type: 3AH-3

9. Vacuum Circuit Breaker Type: 3AH-5 10. Breakers Interrupter Table, Harting plug

description & Breaker-Mech Wiring Dwgs. 11. Sion Circuit Breaker Manual 12. Vacuum Contactor Slideshow 13. 3TL Vacuum Contactors Group Manual 14. 3TL 6 Vacuum Contactor Manual 15. 3TL 8 Vacuum Contactor Manual

16. Vacuum Contactor HR Fuse Types 17. Motorised Racking Manual for NX-Air M 18. Modular Metering & VT Truck Manual 19. Internal Arc Protection Scheme 20. Earthing Switch Operation for NX-Air P 21. Panel, C/B & Contactor Test Sheets 22. Circuit Schematic Drawing of Incomer

23. Circuit Schematic Drawing of Bus-section 24. Circuit Schematic Drawing of Meter Panel 25. Circuit Schematic Drawing of Feeder

26. Circuit Schematic Drawing of Motor Panel

27. Siemens Notepad / Drawing paper


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Vacuum switching technology Arc quenching

During the galvanic separation of the contacts, the current to break produces a metal-vapour arc discharge. The current flows through this metal-vapour plasma until the next current zero. Near the current zero, the arc extinguishes. The metal vapour loses its conductivity after few microseconds already the insulating capability of the contact gap recovers quickly. To maintain the metal-vapour arc discharge, a specific minimum current is required. If this minimum current is not reached, it will chop before the natural current zero. To prevent impermissible switching overvoltages while switching inductive circuits, the chopping current must be limited to the lowest possible values. Using a special contact material, the chopping current in vacuum circuit-breakers is just 2 to 3 A. Due to the fast recovery of the contact gap, the arc is safely quenched even if the contacts are separated right before a state of "current zero". Therefore, the arcing times in the last pole to clear are 15ms as a maximum. Depending on the breaking current and the interrupter dimensions, different contact geometries are used.

Welcome to Siemens Technology

The history of Siemens's manufacture of various typ es of circuit breakers recently achieved its first cen tury. In the past hundred years a very thorough knowledge of all types of switching devices in every possible ty pe of medium have been researched, tested and tried.

So, it would be ironic if the technology which we n ow call "vacuum" was not discovered during the global space age. Unlike to normal air or mixtures of nitr ogen and oxygen a vacuum presents the perfect forum for a safe switching environment being able to minimise arcing and contact burn.


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Key to description of parts:

IInntteerrrruupptteerr DDeessiiggnn The interrupters are of a very compact design as can be seen in the cross-section drawing provided. The area or volume of space occupied within the interrupter is at a perfect vacuum state. This would be the same as if switching the contacts in outer-space, where there is no air, as in "nitrogen" or "oxygen" which could contribute in any way to assist with ignition or explosive tendencies. This compact design of the Siemens vacuum interrupters provides a very high switching capacity in very compact dimensions: for example: vacuum interrupters for 15 kV/40 kA with housing dimensions of 125 mm diameter by 161 mm length, or for 12 kV/13.1 kA with 68 mm diameter by 115 mm length. A very high QA level has been achieved in the product market. This quality assurance is due mainly to Siemens following the TQM and DIN / ISO 9001 procedures & specifications, which call for rigorous material, manufacture & production checking. Every batch is checked & tested individually before delivery and only if the QA result is a 100% pass, are the interrupters released for delivery. Some of the tests that are performed include: testing of the interrupters for assuring the seal of vacuum sealing, testing for reliable long operation and long life, environmental protection involved in the manufacture of these vacuum interrupters and our guarantee to only use environmentally compatible materials, such as copper, ceramics and high-grade steel. Such, that the manufacturing processes do not damage the environment. (e.g. no CFC's are used in production (this fulfilling the Montreal agreement); also all the components are cleaned and kept free from micro-fibres & contamination in a ultrasonic plant, with the entire manufacturing line concealed in a protected atmosphere.

Vacuum interrupters for the medium-voltage range are available from Siemens for all applications on the international market from 1 kV up to 40.5 kV. Vacuum Interrupters are also used in special design applications where the operational voltage that they are exposed to is well in excess of 40.5kV, even up to as high as 132kV. When used in these applications the interrupter is immersed in SF6 Gas within a pressurised chamber, so that the switching of "contacts" are still done within a vacuum inside the interrupter, but therefore in this application the entire interrupter itself is immersed and insulated by SF6 gas. This type of configuration enables using the same switching technology in much higher operational voltages. Applications:

Vacuum interrupters are used in vacuum circuit breakers, vacuum switches, vacuum contactors, transformer tap changers, in circuit breakers for use in railway applications, auto-reclose switches, and lastly also in special applications such as nuclear fusion.

Introduction to the Vacuum interrupters


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Inside the Vacuum interrupter - The Manufacturing p rocess To prove the atmospheric pressure, in 1654 Otto von Guericke created a vacuum with the Magdeburg hemispheres for the first time in history. More than 35 years ago, Siemens developed vacuum switching technology, leading it to series production. What was then a fundamental innovation has been developed further to a proven technology, which now has a worldwide market share of about 70 percent. Vacuum switching technology from Siemens meets all the requirements placed on circuit-breakers and contactors in medium-voltage switchgear up to 40.5 kV, and is now an integral part of many applications because of its clear advantages. The Siemens vacuum interrupters are manufactured inside the Siemens Factory in Berlin under various processes. We will briefly take you on a short journey through this process and discuss some of the important facts of how these vacuum interrupters are made until they are assembled in the form of a finished product such as a Contactor or vacuum circuit breaker. Contact rod processing In our numerically controlled multi-axis lathes, the raw parts are given the external contour and the slots of the contact carrier surface in just one single operation. The fully automatic process reduces the error rate to a minimum. A constantly high quality characterizes the produced parts. Contact material processing Siemens is the only manufacturer of vacuum interrupters worldwide to produce the contact material itself. The basic raw materials copper and chrome are combined to a powerful contact material by means of the arc-melting procedure. The resulting raw parts are processed to RMF or AMF contact discs, whereby the slotted AMF discs are de-bured at the end. All processing steps are electronically recorded for quality purposes. Metallography To fulfil the highest quality demands, samples of the contact material are examined by metallography. Here, the homogeneity of the contact material, the quality of the melting process as well as the brazed connection between the contact material and the contact rod are checked. Endurance test for bellows To enable them to meet the requirements for high endurance in real practice, the bellows are regularly subjected to an endurance test every three months. The test is carried out in a fully automatic test cabin with the travels adjusted to the respective type.


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Vacuum interrupter assembly under clean-room condit ions

After having finished and cleaned the surfaces by electroplating and performed an optical inspection of the surface consistency of all single parts, the interrupter is assembled. The high-vacuum solder is applied at the joints of the components, the parts are aligned, and the interrupters are fixed. As cleanliness during assembly is especially important, all operations are done under air-conditioned "clean-room atmospheric" conditions – in this way we can guarantee a constantly high quality of the interrupters and maximum possible ratings up to 72 kA according to IEEE C37.013. High-vacuum brazing furnace

In the high-vacuum brazing furnace, the joints of the vacuum interrupters are brazed at temperatures up to 900 °C and a press ure of 10-6 mbar. Thus, the interrupters fulfil the quality requirement “sealed for lifetime”. Thanks to the fully automatic production process, the high quality can be constantly reproduced at any time. X-ray test

The evaluation of the interrupters by means of the X-ray procedure is used to verify the positions as well as the completeness of the internal components, and the quality of the brazing points. In this way we ensure the high quality of our products. Forming and high-voltage testing of vacuum interrup ters

During forming, the definitive internal dielectric strength of the vacuum interrupter is established with gradually increasing voltage, and this is verified by a subsequent lightning impulse voltage test. Both operations are done with higher values than those specified in the standards, as evidence of the extraordinary quality of the Siemens vacuum interrupters. This is the prerequisite for a long endurance and a high availability. Switching device production

The switching device production is set up as a direct flow production. Various assemblies are prefabricated in parallel and combined at the mounting place of the switching device. The flow production reduces the order lead times and thus the delivery times of the switching devices to a minimum.

Laser welding

Laser welding provides a completely positive material joint between individual components – as a prerequisite for highly resistant, dynamically stress able assemblies such as the operating mechanism box. Its superiority over conventional welding becomes apparent, above all, by the fact that no hollows are produced – which would be susceptible to humidity – and that the material cannot loose shape anymore. The consequence: a high dimensional accuracy with the lowest tolerances possible – and thus, reduction of later adjustments to a minimum. Stamping and laser cutting

In the pre-production, the steel plates are processed by highly automatic and highly productive stamping and laser cutting machines – providing the assured adherence to minimum tolerances, even with high quantities. The high degree of automation results in a process-safe, trouble-free production with short lead times, almost without any down time. Loading, operating and programming is possible with the machine running, without interrupting the production process.


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Surface Treatment

Electroplating is used to improve the material surfaces and to protect them against corrosion. By plating with a second material, the mechanical and electrical properties of the carrier materials are sustainably improved. This provides an optimised surface – which is decisive for a longer service life of the product and its permanently maintenance-free design. Final assembly of switching devices

For all switching devices, the individual constructional units are pre-assembled in parallel. During final assembly, the different constructional units, the pole structure as well as the operating mechanism box are combined, and the device is equipped with the order-specific secondary system. Parallel work operations reduce the production lead time of the switching device to a minimum – sometimes even short-term customer requirements can still be implemented. Final inspection and testing of circuit-breakers

After having passed the routine and high-voltage tests successfully, the circuit-breakers are inspected at the final testing station to detect visible sources of faults. The rating plate is not attached until this last visual inspection has been completed successfully, and then the circuit-breaker is released for dispatch. To reduce complaints to a minimum, the order is checked for completeness and conformity before leaving – after all, you are expecting quality in every detail.

& finally the finished products:


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The Electro- Magnetic Concept of how a Vacuum Inter rupter works: Definition of a Vacuum Interrupter: A vacuum interrupter is an operable single contact that has been homogeneously sealed during its manufacture, in such a way that the atmosphere within the interrupter, which would normally be present around the contact surfaces, has been totally withdrawn or "sucked out" of the inside chamber and then simultaneously sealed immediately thereafter. In this sealed form there is then no atmosphere, particles that may be ionized, or any gases present that may contribute to igniting any type of flame or burning from an arc around any of these contact surfaces inside the interrupter. This making it almost impossible for any combustion or burning to take place during the arcing-time that would usually occur during an "on" or "off" operation of the circuit breaker. The interior part of the interrupter is therefore at total vacuum potential, i.e. equivalent to the conditions that would normally be found in outer-space. The top pole contact of the interrupter is usually fixed and the lower contact is the one which moves up and down to achieve the operation. The interrupters on a circuit breaker truck are usually 3 that are mounted side by side for the 3 phases usually required for industrial electrical operations on plants. Vacuum Interrupters are also hugely environmentally friendly, as they will maintain and contain all their lifetime of switching gasses and debris, inside their own sealed housing during their full service lifetime, which can range up to 25 years pending certain operational circumstances. During operation vacuum interrupters are also themselves not affected by the environment, as they have been completely sealed with special materials such as porcelain. Philosophy of the - In radial magnetic-field contacts, the arc burns diffusely until approx. 10 kA (momentary value). Higher currents burn across a contracted arc. In this case, local overheating of the contacts must be avoided. An additional magnetic field thus produces this required force, which makes the arc rotate on the arcing rings of the contacts via the magnetic field generated by the flow of current through the contact tips. Thus, contact erosion at the base point of the arc is distributed over the entire ring surface at a completely even rate.


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Philosophy of the - In axial magnetic-field contacts, the arc remains diffuse, even with high currents due to the axial magnetic-field. The disc-type contact surfaces are uniformly stressed, and localised melting is avoided. In alternating-current circuit breakers, the actual function of the quenching system is to de-ionize the contact gap immediately after current zero. For all conventional quenching systems, this means that the arc must already be cooled before reaching the minimum quenching distance and the following current zero. Involuntarily, this increases the arc's power a lot (magnetic component), resulting in it responding better to following the magnetic field that develops between these two contact surfaces . In the case of vacuum circuit-breakers, however, the arc is not cooled down. The metal-vapour plasma is highly conductive. This results in a very small arc voltage ranging between 20 and 200 V. For this reason, and due to the short arcing times, the energy converted in the contact gap is very low. Because of this relatively low stress, the quenching system is maintenance-free. In stationary condition, the pressures in the interrupter is very low – less than 10-9 bar, so that contact distances of just 6 to 20 mm are required to reach a very high dielectric strength. Apart from circuit-breakers, the vacuum switching technology can also be used in contactors and other type of switches such as barrel switches. Today, more than 70% of all circuit-breakers installed in medium-voltage systems are based on vacuum switching technology.

CROSS-SECTIONAL SIDE VIEW OF AN INTERRUPTER

HIGH-SPEED CAMERA SHOTS OF THE "ARC DISSIPATION" ON A POLE CONTACT SURFACE OPENING

UNDER REAL FULL-LOAD CONDITIONS


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Maintenance and servicing

Symbols used Operation symbol: Identifies an operation. Asks the operator to perform an operation. Result symbol: Identifies the result of an operatio n. 1.1 General instructions Independently of the safety instructions given in these operating instructions, the local laws, ordinances, guidelines and standards for operation of electrical equipment as well as for labour, health and environmental protection apply, and these are to be complied with, in line with the latest Regulations. All methodologies & actions applied to any services of the equipment or to repairs are to comply with specified methods as described and discussed in the Siemens specific procedure relevant to the equipment and parts in question. All work performed, whether on site or in the works, of whatever nature, must comply with the ACT. 1.2 The Five Golden Safety Rules of Electrical Enginee ring The Five Safety Rules of Electrical Engineering must generally be observed during operation of the products and components described in these operating instructions:

Isolating.

Securing against reclosing.

Verifying safe isolation from all sources of supply .

Earthing and short-circuiting methods are safe & ca n withstand kA rating.

Covering, tagging and locking out of all adjacent l ive parts and shutters.

1.3 Delivery in line with Specifications The switchgear corresponds to the relevant laws, pr escriptions and standards applicable at the time of delivery. If correctly used, they provide a high degree of safety by means of logical mechanical interlocks and shockproof metal enclosure of live p arts.


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1.4 Qualified personnel – Training and legalities

Qualified personnel in accordance with these instru ctions, are persons certified or qualified to under take this type of work, either by certification through some form of education, studies, or training, which can be backed up by a recognized certificate, degree, or letter o f appointment. For such persons, or qualified Elect rical Artisans, Technicians and Engineers, that are permi tted by their organisations, the National Regulator , or any form of other legally acceptable appointments, who are similarly familiar with the regulatory requirem ents and the safe operational safety requirements of these p roducts and also have the appropriate qualification s for this "type of work", must also obtain the necessary back ground knowledge about the transport, installation and commissioning of these products. Therefore these pe rsonnel must have also participated in this trainin g course for "The first line safety, operation and maintenan ce" requirements of the Siemens air-insulated mediu m-voltage switchgear type "SIMOPRIME".

The aim of this training, is that it provides a fir m basis of "safety awareness, knowledge and underst anding of the equipment" in the form of detailed information about the design, operation, installation, testing and troubleshooting of the SIMOPRIME switchgear. After successful participation, the participants of this training course get a certificate of Competence to operate a nd perform the first line maintenance for this "spe cific" type of equipment only, as the minimum required training for performing operations on specific electrical a pparatus, or as usually specified under the regulation, the A ct or by the D.O.L.

The certificate for this course only authorises the participants to be appointed to "switch" or "opera te" the Siemens "specific" equipment, but then also only af ter they have fully satisfied the D.O.L., the N.R.S ., the Act & any other regulatory requirements required by the l aw, to perform "MV switching", within their specifi c "place of work", as the authorised or responsible person, and that he or she has been fully trained on all the p recautions and dangers that are associated with this specific process. The certificate of this training will only allow the operator to switch "Siemens type Simoprime medium v oltage switchgear" electrically, provided that he i s certified on HV Regulations, has a letter of appoin tment to do this switching for and on behalf of his /her employer, and has been appointed by letter, as the Operational or Responsible person to do such.

The attendee therefore acknowledges and realises, t hat by signing the attendance register, that it is up to his "own full responsibility" to ensure his/her underst anding of the subject matter, credible certificatio ns to perform the work and understand and apply the regulatory re quirements, that are covered herein, so that at the end of this course, they do not leave the venue with any r emaining questions or uncertainties, to ensure that he or she has satisfied their every curiosity, or remaining q uestions that they may have had, in terms of the Sa fety aspects of the operations and functions of this equipment.

Siemens cannot be held liable, or will not accept a ny liability, or responsibility, for the direct or indirect actions of any customer staff, that are out of, or beyond o ur control, supervision, or deviate from any regula tion, even if by accident or omission, or even if such procedures may be covered, yet have been misunderstood in thi s training course which has been presented. It is the attendees own responsibility at the end of this co urse to ensure that all the procedures and legal requiremen ts of the NRS, the Act and any additional safety re gulations, such that may be required by such as even their emp loyer, are all implemented, understood and upheld b efore performing any work in the field.

The Completion of this course does not authorize staff to be appointed to do any "Switchi ng". This is a separate course on offer, which covers the regulations and t he Act and is referred to as "High Voltage Switchin g Regulations Training". For further information abou t this training, please contact: Niels Inderbieth en, on cell – 072 287 4525, who will arrange for a quotation for the course to be held either on our, or the clients own premises.

We wish you a pleasant learning experience in atten ding this Siemens Training Course…

With our sincere thanks… from all of us… at…

SIEMENS LTD SOUTH AFRICA

Establishing safe conditions first, before the exec ution of any works


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Furthermore, qualified personnel must have the foll owing training and authorisation:

Training and instruction or authorisation to switch on, switch off, earth and identify power circuits and equipment / systems as per the r elevant safety standards (and the recently added new requirements by law, such as HV Reg's & legal appointments)

Training and instruction about the relevant safety standards and the use of

appropriate safety equipment specifically relevant to the equipment they will be switching (such as this course).

Training in first aid and emergencies behaviour in the event of possible accidents or

evacuation requirements relevant to their specific plant i.e. (plant specific)


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1.5 Discussion of the features within the 3AH & K (New ) operating mechanism.

The operating mechanism is fitted with an integrated mechanical interlock which prevents dangerous switching conditions or operations from being carried out when the power is on.

The operating mechanism unit is only found on trucks fitted with a circuit-breaker.

The mechanism is fitted with isolating contacts that indicate the breaker position during racking.

Mechanical interlocks are provided to safeguard the operator during racking procedures.

Visual racking control status is provided with graphic representation.

The operating mechanism is fitted with a closing solenoid allowing for remote "close" control.

Mechanical indication of “closing spring charged” indicator can be seen through front of truck cover.

The first shunt release coil, which is also used for remote tripping, is the electrical tripping solenoid which mechanically pushes against the trip lever that triggers the trip roller bearing.

The mechanism is fitted with an operating cycle counter, which counts every open and then closed operation as one single operation increment on the counter.

Other solenoids may also be additionally fitted to extend the conditions of the trip operations, these include under-voltage coils and uniquely driven shunt-trip coils. The circuit-breaker tripping signal can also be additionally routed through protection relays and logic contacts to extend the desired level of protection.

The circuit breaker mechanism is fitted with an electrical anti-pumping device which prevents more than one auto re-closure, when the breaker is switched back on a fault that has still not cleared.

Varistor module fitted for the auxiliary voltage W 60 V, the auxiliary switch has 6NO+6NC contacts.

1.6 Parts of the 3AH5 circuit breaker operating mechan ism:


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1.7 Nameplate:


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1.8 SION vacuum circuit breaker. Component Identifications: Part identification & features of the SION Operatin g Mechanism. Component Identifications:


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Maintenance and servicing 1.9 General Maintenance The vacuum circuit-breakers / contactors switchgear are maintenance-free within the scope of the permissible number of operating cycles. Under norma l environmental and operating conditions the maintenance intervals are longer than five years. B uilt-in equipment such as voltage transformers, current transformers, relays, meters, protection eq uipment, etc. must be serviced and maintained as specified in the associated operating instructions.

Commercially available tools are sufficient for car rying out the maintenance work.

After maintenance, put the equipment again into ope ration as per the operating instructions.

Carry out maintenance and servicing at shorter inte rvals (to be specified by the owner) if there is a lot of dust, or if the air is extremely humid and/or polluted.

Grease main fixed contacts of bushings and fixed co ntacts of earthing switches as well as other surfaces exposed to friction (e.g. shutter op erating linkage, guide rails) at shorter intervals (to be specified by the owner): Tin of Lo ng-term 2 grease (8BX1022).

Independently of the regular maintenance, immediate ly determine the cause of faults and short circuits and replace any damaged components.

Maintenance intervals The maintenance intervals described hereafter are a recommendation when the switchgear is operated under normal environmental conditions. In case of extreme operating conditions the maintenance intervals must be adjusted accordingly. Annual maintenance Carry out general check for damages, dust layers, h umidity in the switchpanels, and for partial discharge noises. Check whether accessories are complete and in good condition (including the truck). Maintenance after five years

Operate earthing switches for test.

Clean switchpanels.

Check function of switchpanels and put switchgear a gain into operation.

Check primary connections of current and voltage tr ansformers.

Check bolted joints (see "Installation", Section 9. 2, Page 32). SAFETY FIRST - Maintenance of vacuum circuit-breake r / vacuum contactor

Preconditions: • Supply voltage switched off

• Circuit-breaker in OPEN position

• Spring not charged


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Niels Inderbiethen

Specialist – Technical Support FAC/ASS ETDPSETA SAQA AcrNo:ATS/12/2838

MCS (Metering) & PTI (Training) Services SG Services (Smart Grid) Siemens Southern Africa

IC Sector (Infrastructure & Cities) Newmarket Street, Northriding

T: +27 10 222 7315 F: +27 86 506 5941 M: +27 72 287 4525

[email protected] www.siemens.co.za

- END OF THIS TRAINING ADDENDUM MANUAL -

NNB

(PLEASE REFER TO THE DIFFERENT NX-AIR W, M&P SWITC HGEAR PANEL

DOCUMENTATION FOR A FULL DESCRIPTION OF RACKING IN THE RACKING ORR MOTORISED RACKING OPERATIONAL PROCEDURES.

ADDITIONAL INFORMATION ON THE CIRCUIT EXAMPLE DRAWI NGS FOR THE CUSTOMERS SWITCHBOARD (SINGLE LINE DRAWINGS AND THE 3AH CIRCUIT BREAKERS WIRING DIAGRAMS) IS ALSO PROVIDED IN THE L AST SECTIONS, SECTIONS 22-26 OF THIS MANUAL)

training course nx-air intro & safety

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