Std-146

OISD-RP-146 First Edition October, 1993 Amended edition, August 2000

FOR RESTRICTED CIRCULATION

PRESERVATION OF IDLE ELECTRICAL EQUIPMENT

Prepared by COMMITTEE ON INSPECTION AND MAINTENANCE OF ELECTRICAL EQUIPMENT

OIL INUSTRY SAFETY DIRECTORATE 2ND FLOOR, “KAILASH” 26, KASTURBA GANDHI MARG

NEW DELHI 110001

NOTE

OIL INDUSTRY SAFETY DIRECTORATE (OISD) publications are prepared for use in the Oil and Gas Industry under Ministry of Petroleum and Natural Gas. These are the property of Ministry of Petroleum and Natural Gas and shall not be reproduced or copied and loaned or exhibited to others without written consent from OISD. Though every effort has been made to assure the accuracy and reliability of the data contained in these documents, OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting from their use. These documents are intended to supplement rather than replace the prevailing statutory requirements. Note 2 in superscript indicates the modification/changes/addition based on the amendments approved in the 18th Safety Council meeting held in August,2000.

FOREWORD Oil Industry in India is more than 100 years old. Due to various collaboration agreements a variety of international codes, standards and practices are invogue. Standardisation in design philosophies, operating and maintenance practices at a national level was hardly in existence. This lack of uniformity coupled with feedback from some serious accidents that occurred in the recent past in India and abroad, emphasised the need for the industry to review the existing state of art in designing, operating and maintaining Oil and Gas installations. With this in view, the Ministry of Petroleum and Natural Gas in 1986 constituted a Safety Council assisted by the Oil Industry Safety Directorate (OISD) staffed from within the Industry in formulating and implementing a series of self-regulatory measures aimed at removing obsolescence, standardising and upgrading the existing standards to ensure safer operations. Accordingly OISD constituted a number of Functional Committees comprising of experts nominated from the industry to draw up standards and guidelines on various subjects. The present document on “Preservation of Idle Electrical equipment” was prepared by the Functional Committee on “Inspection and maintenance of electrical equipment”. This document is based on the accumulated knowledge and experience of industry members and the various national and international codes and practices. It is hoped that provisions of this document if implemented objectively, may go a long way to improve the safety and reduce accidents in Oil and Gas industry. Users are cautioned that no document can be a substitute for the judgement of responsible and experienced engineer. Suggestions for amendments, if any, to this document should be addressed to: The Coordinator Committee on “Inspection and Maintenance of Electrical Equipment” Oil Industry Safety Directorate 2nd Floor, “Kailash” 26, Kasturba Gandhi Marg

NEW DELHI – 110001 This document in no way supercedes the statutory regulations of Chief Controller of Explosives (CCE), Factory Inspectorate or any other statutory body which must be followed as applicable.

COMMITTEE ON INSPECTION AND MAINTENANCE OF ELECTRICAL EQUIPMENT LIST OF MEMBERS Name

Designation/Organisation

Status

B.B. Chakravorthy

DGM (SA&PC) IOCL (R&P)

Leader

A.K. Anchan

Chief Mgr. (Elect) HPCL (R )

Member

M.J. Bordoloi

Suptdg. Engr. (Elect) OIL

Member

A.P. Kant

Project Mgr. (Elect. Inst) BRPL

Member

George P. Paret

Sr.Mgr. (Proj.Elec) CRL

Member

R. Sankaran

Sr.Mgr. (Mtce. Elect) MRL

Member

R. Srinivasan

Sr. Mgr. (Mtce. Elect) BPCL (R )

Member

S.C. Upadhyaya

DGM (Elect) ONGC

Member

N.V. Mani

Joint Director OISD

Member Coordinator

S/Shri

In addition to the above, several other experts from industry contributed in the preparation, review and finalisation of this document.

PRESERVATION OF IDLE ELECTRICAL EQUIPMENT CONTENTS ________________________________________________________________________ SECTION DESCRIPTION PAGE NO. 1.0 Introduction 2.0

Scope

3.0

General Guidelines

4.0

Rotating Equipment

4.1

Motor (in warehouse)

4.2

Motor (in field)

4.3

Generator (in service)

5.0

Static Equipment

5.1

Transformer

5.2

Switchgear

5.3

Cable and Conductor

5.4

Battery

5.5

UPS (Uninterrupted Power System)

6.0

Spares in Stores

6.1

Relay, Instrument & Meter

6.2

MCC, PCC, Breaker

6.3

Motor

6.4

Switchfuse and Fuse

6.5 7.0

Lighting Fixture Newly Received Equipment

8.0

References

PRESERVATION OF IDLE ELECTRICAL EQUIPMENT 1.0

2.0

INTRODUCTION

iii)

The nature of preservation of idle electrical equipment varies with the size, location, and anticipated idle time of equipment. Electrical equipment located outdoor in the plant area are more susceptible to effects of rain, dust, corrosive and other extreme weather conditions. In addition to own specific preservative requirements, all equipment in general should be kept trouble free by periodic checking, and keeping them clean, dry an friction free. Preserving and protecting the idle electrical equipment as per the guidelines given in this document will go a long way in ensuring safer operations of the installations in the Oil industry, whenever such equipment are taken into service after their idle period.

The steps to be taken to preserve the idle electrical equipment in the above first two categories when they are idle in the field and for all the categories when they are in storage are specified. Additional requirement for preservation applicable specially for newly received equipment are also discussed.

SCOPE This document recommends minimum safe practices and procedures to be adopted for preservation of electrical equipment, which, after their repair/reconditioning, or overhaul are either kept in storage or temporarily removed from service and kept at site. This also covers preservation requirements for idle equipment in the field which are deenergised. The electrical equipment covered are generally categorised as follows: i)

Rotating equipment such as Motors, Generators etc.

ii)

Static equipment such as Transformers, Switchgears, cables, Battery, UPS, etc.

3.0

Spares in stores.

GENERAL GUIDELINES The storage area of electrical equipment and spares, should be dry, well ventilated, free from fire hazards and adverse effects of environment. In such area, the housekeeping should receive best attention. The treatment needed for the preservation and protection of idle electrical equipment, against external factors would widely vary depending also upon material of construction. In corrosive atmospheres, cast iron castings of electric motors, motors starters, gearboxes etc. normally do not need any further protection to resist corrosion. Such castings though have reasonably good life in corrosive atmospheres, are liable to develop cracks during handling. Therefore, special care should be taken in their handling especially in the case of flameproof electrical equipment (whose flame proofness will be adversely affected due to any damage/crack on the equipment). Any material or component of equipment made out of an iron alloy (such as silicon and iron) should also be carefully

handled since such materials are brittle and are not readily weldable.

be handled carefully since these materials are rather brittle.

Mild steel materials of construction should be applied with anticorrosive painting and such other treatment for preservation, as recommended by the manufacturer, to avoid the adverse effects caused by acids, caustic solutions, organic solvents etc. (which cause embrittlement at high temperature and rusting at atmospheric conditions).

Wooden boxes/cases, Cable drums etc. should not be stored outdoors open to direct rains, waterlogged areas, high temperature zones. The wooden materials should not become wet (because when wet, all wood expand and while getting dried out later, after once wet, warpage would occur mostly). Whenever new equipment is received at site or in stores, manufacturers’ recommendation for preservation should be followed. Also additional instructions given in Section 7.0 should be followed.

Similarly in case of equipment or component whose material of construction is of non-ferrous metal such as Aluminum, Tin, Nickel, Chromium, Copper, Zinc, Lead and lloys (Bronze/Brass) etc. or of Plastic material, special precautions should be taken in their preservation, some of which are described below: •

• •

Aluminum, which is mainly used as electrical conductor should be preserved against oxidation in contact with moist air, and its attack from acids and alkalis. Ebonite is used in bushes, which are hard rubber and quite brittle, and should be handled carefully. Plastic materials should be protected from the attack from organic solvents (such as Carbon Tetrachloride) causing swelling. Thermoplastic materials (such as polyethylene – polythne) which are used as cable covering, packaging materials etc. Should not be subjected to heat because these materials soften when heated and original moulded shape gets altered. Electrical fittings/covers are sometimes made of Bakelite (thermosetting phenolic resins) which should

Electrical circuits on idle units (except those required for lighting, emergency power, or special heating, or transformers which are kept energised etc.) should be disconnected from supply source.

Idle equipment should be properly tagged and connections identified. These should be easily accessible and stored at dry and wellventilated places. In addition to complying with the above general guidelines as applicable, the preservation procedures for individual type of equipment should be adopted additionally as given in the succeeding sections respectively. Wherever equipment, such as switchgear panels, are kept energised but isolated from service (i.e. idle). Preventive Maintenance Inspection Schedule should be followed as per OISD-STD-137.

Periodic inspection of protective coating of preservatives on machined parts of equipment such as motors (in case of long storage period) deserves special attention. Storage place should be free from corrosive atmosphere due to SO2, Chlorine gases etc.

i)

The place of storage should be clean, warm, dry and well ventilated covered shed. The area should be free from direct sunlight, excessive temperature changes and vibrations.

ii)

Ventilated machines should be installed in a position permitting full flow of air, not exposed to moisture, dust, steam or dangerous gases or adjacent to furnaces etc. where radiated heat may cause excessive machine temperatures.

iii)

The spaceheaters should be connected wherever available. The motors which do not have spaceheaters should be preserved such a way that body temperature is kept at around 10oC above ambient.

iv)

The shaft of the rotors should be rotated every month.

v)

While in storage, a machine with antifriction bearing should not be subjected to vibration since damage may be caused by fretting corrosion or static vibration marking. If vibration cannot be avoided the machine should be mounted on resilient mats and the rotating parts turned by hand about half a revolution at weekly intervals, or alternatively the rotor should be locked. This also applies to a stand-by machine.

For any such cases of preservation of electrical equipment under conditions specific to particular installation which may not be covered in this document, manufacturer’s instructions should be sought by the user organisation. 4.0 4.1

ROTATING EQUIPMENT

MOTOR (IN WARE HOUSE)

Because of their proximity to rotating and material transfer equipment, electric motors are frequently subjected to environmental conditions that are detrimental to the life of the equipment. In most installations, they are in constant contact with acid vapours, water vapours, harmful dust, and such other elements. Designers of electric motors have taken these factors into consideration, but because of variations of service conditions and severity of services, it is not possible to design the equipment suitable for all conditions. The motors which are of open or semi open enclosure type should be overhauled as detailed in OISD-148 before taking them into storage. For TEFC motors, if the overhauling has taken place in the preceding six months further overhauling is not necessary. During storage, the following should be ensured:

vi)

• • •

If the insulation resistance is low, which will most probably be due to dampness, the machine should be dried out by one of the following methods: Bake the machine in an oven (but do not allow the temperature to exceed 75oC) Blow clean dry air into the machine not exceeding 75oC. Place filament lamps inside the machine but ensure that the bulbs do not make contact with the windings.

(The insulation resistance will drop considerably as the machine warms up, but as drying out proceeds, it will gradually increase. The drying out should be continued as long as the insulation resistance rises or until a sufficiently high value is reached i.e. not less than 1 Megaohm per 1000 Volts at 75oC.) During the drying out period, readings of temperature and insulation resistance should be taken regularly to observe progress. The temperature should be kept as constant as possible, otherwise readings may be misleading. vii)

4.2

The rating plate of the motors should be clearly visible and should not be painted.

MOTOR (IN FIELD) Motors in the field have to be kept covered properly to protect from effect of rain, water spray, fire hazard etc. The following procedures should also be adhered to:

4.3

i)

Isolate the power supply and control supply of the motor in the concerned SWG/PCC/MCC. However, retain the space heater supply. Note 2

ii)

Top up the lubricant in the bearing housing

iii)

Decouple the motor and run once a month, for at least 1 hour duration. In case of large size motors if decoupling is not desired, then functioning of spaceheaters shall be ensured such that body temperature is maintained at around 10oC above ambient.

iv)

Ensure preventive maintenance schedule is followed. When electrical motors are to remain in the field and continue to exist in corrosive and harmful environments or when space heater is not available, manufacturer should be consulted for prescribing appropriate procedure for preservation, applicable under such specific condition, which should be followed.

GENERATOR (IN FIELD) Note 2 The generator should be preserved in-situ where no leakage or uncontrolled release of steam, water, oil etc. is ensured so as to ensure clean, dry and dust free environment. The following items should be checked every six months and corrective actions be taken

(except once in 3 months for item (I) and once in 15 days for item x). i)

ii)

Insulation resistance & Polarisation Index values for stator & rotor and the same should be recorded. Condition of generator Coolers, cooling piping/ducting and apply anticorrosive paint, if corrosion effects are noticed.

iii)

All couplings to be inspected (for corrosion, if any) and should be smeared with oil/grease.

iv)

Lubricating system, specially for the contamination of lubricant.

v)

All bus ducts for proper sealing.

vi)

All brushes (the brushes should remain out from brush holders)

5.0

xi)

Apply anti-corrosive paint on the metallic parts of in the body support and inspect the condition of support.

xii)

Apply oil or grease as recommended by the manufacturer to the bearings and inspect the condition of bearings.

STATIC EQUIPMENT In general, all static equipment installed at site should be kept energised even during their idle periods. In such cases, the preventive maintenance schedule as per OISD-STD-137 should be followed. Due to any reason, if it is not feasible to keep such idle equipment energised, the guidelines given in this section, for their preservation, should be followed.

5.1

TRANSFORMER

vii)

Operations of all auxiliaries of the generator, for healthy condition.

The following procedure for preservation should be complied with:

viii)

Ensure spaceheaters continuous operation.

i)

Disconnected the electrical circuits from all sources of power supply.

ix)

Maintain the body temperature around 10 degree C above ambient to avoid condensation of moisture on the windings.

ii)

Clean all power bushings with an appropriate nonabrasive cleaning solution, brush, or cloth.

iii)

Inspect for cracked or chipped porcelain, and replace bushings as necessary.

iv)

Check the fill level on oil and gas-filled bushing.

x)

in

Barring of the rotor should be done every15 days. Ensure lube oil system is in operation during Barring.

v)

Clean and paint or grease metal parts.

vi)

Check the fill level, dielectric strength, and contaminates content of the transformer oil, and recondition if required.

and should be dry, cool, dust free and well ventilated. ii)

vii)

viii)

ix)

x)

xi)

In case of OLTC (On Load Tap Changer) Transformers, characteristics of oil should be checked from the main tank as well as from OLTC. If the bus duct forms an integral part of transformer, the preservation procedures for normal panels should also be applicable to bus ducts. Wherever Transformers are provided with cooling fans, the same should be checked for proper functioning. (the fan motors should be preserved as mentioned in the Section on Motors). In absence of a dehumidifier, the Silicagel breather should be put in service and condition of silicagel be checked weekly. Dielectric strength and other parameters as required in IS:335 of oil should be checked once in three months.

The following factors should be taken care during storage; i)

the place of storage should be a covered shed, free from fire and explosion hazards,

The transformer should not be stored out doors directly without ensuring: a)

Conservator oil filter flange dummy cap is air-tight.

b)

Explosion vent diaphragm is in tact and not broken.

c)

Breather pipe cap is air tight.

d)

Oil is filled up to Minimum oil level in conservator and there is no leakage through inspection hole, in top cover, bushings, radiator joints, thermometer pocket, and air release plugs.

( The above will ensure that rain water does not find its entry into the transformer). iii)

When the oil is received in drums, it should be ensured that the ‘seal’ is in tact so that the moisture would not contaminate the oil. The oil drums should be stored under shelter where temperature variations are minimum and in a place free from fire and explosion hazards. The oil drums should not be stored standing on ends, but stored horizontally with filling and air release caps covered under oil.

iv)

v)

vi)

5.2

If the water finds its entry into the tank, due to improper storage, damage during transit etc. drying out should be necessary, through one of the approved methods of drying as specified in the IS:335/IS:10028. Loose accessories like bushing, explosion vent, buchholz relay, temperature indicators, oil gauge etc. should be preserved in original. Radiators dismantled for the transport be packed separately with both ends hermetically sealed with blanking plates.

temperature is maintained 5 to 10oC above ambient to prevent condensation of moisture on busbars, terminals etc. 5.3

CABLE AND CONDUCTOR The following procedure preservation should be adopted:

5.3.1

Cable in storage i)

Normally cables are supplied in drums. The guidelines given in IS:1255 and IS:1554 for care to be taken for the cable drums should be followed.

ii)

If the end terminal sealing of cable was removed (for checking) on its receipt, the same should be sealed back again.

iii)

PILC Cables have insulating liquids inside the lead cover. In course of time, this insulating liquid may settle in the bottom half of the cable drum. In such cases, the cable drum should be rolled half circle every 3 months.

iv)

Cable drums should be stacked in paved and welldrained area segregated as per size and voltage grade of cable.

v)

Surplus cables (upto size 19 mm O.D) may be stored in coils for max. 500 mts length. Beyond 500 mts, they should be kept in cable drums. Storage drum should be of proper size for

SWTICHGEAR Switchgear panels kept in the warehouse should be preserved well in an enclosed shed/well ventilated and dust free atmosphere. All panel covers should be in position and locked properly to avoid ingress of foreign materials/lizards etc. The following preservation procedure should be followed which are already installed at site but isolated from service and kept de-energised: i)

Disconnect electrical circuits from all sources of power supply

ii)

Space heaters provided inside the primary enclosures should be checked for proper operation. Wherever space heaters are not provided, provision should be made for installing heaters. It should be ensured that body

of

a particular size of cable as per BIS. vi)

5.3.2

5.3.4

Cable laid (But out of service) i)

ii)

iii)

iv)

v)

5.3.3

Metallically sheathed power cables for underground use should be inspected periodically and protected from corrosion effects.

ii)

Overhead Power Line When the line is charged, preventive Maintenance schedule as per OISD-137 should be followed. When the line is de-energised, the following should be carried out/ensured every three months, except item (vi) once every year.

Disconnect at both ends from the source and equipment. Ensure that the disconnected ends of leads are properly taped and sealed for protection from weather conditions (such as entry of water/effect of moisture).

i)

Line patrolling

ii)

Vegetation growth, if any, is to be cleared

iii)

Alignment of cross arms/insulators is correct

iv)

Earthing of posts is effective

v)

Guy wires/stray wires/cradle wires are in good condition

Both LT and HT cables should be tested for leakage current as per the Test method specified in BIS once every year.

vi)

Cleaning of insulators

vii)

Unauthorised construction in the Right-of-way should not be allowed

There should be no damage for the cable trench especially cover slabs, and no part of the underground cable should be exposed.

viii)

Designed sag should be checked and maintained.

ix)

All steel structures/poles/towers should be well painted and maintained properly.

x)

Danger/warning caution boards displayed should be in tact and well maintained.

The taped ends should be kept in upright position and should not be in the vicinity of water logged area. Cable ends should be protected from mechanical damages.

ACSR conductor i)

The conductors should periodically be inspected as per OISD-137 to ensure that there are no corrosion effect and other mechanical damages.

It should be ensured that the ends of conductor be wrapped tightly with a wire so that the strands do not get loosened.

5.4

BATTERY

The battery should be preserved insitu and preventive maintenance schedule should be followed as per OISD-137. If battery is required to be laid off for a long period, and taken to storage, the following procedure for preservation should be followed: i)

The cell accessories after provided with labels for identification should be kept along with the cells.

ii)

Ensure that the caps already mounted on the cells are tight. Fix the adhesive tapes on these caps for safety.

iii)

The cells should be arranged in the stores on stillages or seasoned wooden racks so that there is at least about 10 mm spacing between two adjacent cells.

iv)

v)

The storage space should be inside the building. It should not be a temporary shed lying outside any building. There should not be direct sun rays or any opening in the building leading to a possibility of rain water or moisture creeping inside the room.

vi)

The room should be well ventilated so as to keep the atmosphere cool.

vii)

The battery should be preferably stored on the ground floor.

viii)

The cells should never be stacked directly on the ground as there is always a

risk of the ground being flooded with water resulting in humid conditions around the cells. ix)

Acid container supplied along with cell, should be carefully stored away from Sun and Rain.

x)

Acid container should be properly tagged to avoid misuse.

xi)

Acid container should be preferably kept in an isolated area/room and on the wooden (seasoned Teak Wood)/plastic platform.

xii)

Room should have proper acid proof flooring with water washing facilities.

xiii)

Room should have ventilating fans working all the time.

xiv)

Acid Container should be periodically checked. Damaged or leaking ones should be disposed of as per standard handling procedures indicated by manufacturer.

xv)

Thoroughly clean the positive and negative terminal lugs and the inter connecting strips and protect them from corrosion by smearing a light coat of petroleum jelly.

xvi)

Ensure that petrol, oil, grease etc. do not come in contact with the plastic containers.

5.5

UPS (UNINTERRUPTED POWER SYSTEM)

iii)

All small spares are preserved in transparent closed P.V.C. containers with labels.

iv)

The storage area should be dry, well ventilated and free from fire hazards.

When UPS is idle, the following should be ensured:

6.0

i)

All breakers and switches etc. are turned off.

ii)

Battery is disconnected.

iii)

Panel is covered to prevent dust entry.

iv)

Preventive maintenance checks are carried out every fortnight.

v)

For battery the instructions given in Section 5.4 are followed.

vi)

The air conditioner of the room where the UPS is installed is kept ‘ON’ all the time.

SPARES IN STORES The spares should be preserved in such a way that there should be no damage or deterioration to them during storage, so that these can perform normally when required to be used. The following procedure should be ensured for preservation: i)

ii)

The spares are stored in racks in open condition with catalogue identification numbers and are easily accessible. Care is taken to avoid damages especially to porcelain bushings, glass and other non-ferrous items.

6.1 RELAY, & METER

INSTRUMENT

After inspection, the Relays and Instruments and electronic devices should be sealed in the same packing and be preserved in cool and dry place. Electronic devices/thermostat components should be stored in dust free (preferably air-conditioned) atmosphere, and there should be control on temperature and humidity in the room these are stored in.

MCC, PCC, BREAKER These spares should be preserved in sealed P.V.C. packs. 6.3

MOTOR

The spare motors should be stored in a covered shed with space heaters connected wherever available. Other motors which have no spaceheaters shall be preserved at around 10oC above ambient. Coil for HT & LT motors should be stored in original packing with PVC covers, and should be in dust free, dry atmosphere. The bearing should be preserved as per manufacturer’s recommendation.

The shaft of the rotors should be rotated every month wherever feasible. While in storage; a machine with anti-friction bearing should not be subjected to vibration since damage may be caused by fretting corrosion or static vibration marking. If vibration cannot be avoided the machine should be mounted on resilient mats and the rotating parts turned by hand about half a revolution at a time at weekly intervals, or alternatively the rotor should be locked. This also applies to a standby machine. 6.4 SWITCHFUSE FUSE

instructions/precautions, for new equipment: i)

At the time of receipt at site, all damages (such as even hairline cracks in Bushing/Insulator and also damages like dents, oil leakage etc.) which might have occurred during transit and defective/short supply etc. should be noted and arrangement for repair/replacement with new ones should be made.

ii)

Till the erection site is ready for receiving the equipment, the original packing/crate should not be disturbed.

iii)

In case the storage is for a prolonged period (say more than 1 year), anticorrosive painting should be given on the metallic surfaces/structurals and antitermite treatment should be applied for wooden cases/crates etc.

iv)

Cable drums are to be wedged tightly to prevent rolling or shifting.

v)

The equipment filled with insulating oil should be tested for oil dielectric strength and if it failed during dielectric test, the oil should be reconditioned/replenished as per the BIS recommendation.

vi)

Cable drums should be protected from rain and heat.

AND

All types of switches, fuse carriers and fuses shall be preserved in their own original packings with labels indicating type, rating & size of the switch fuse, fuse elements/carriers, in shelves/racks. 6.5

LIGHTING FIXTURE

These shall be stored taking care to avoid damages and stacked properly for easy identification. The fixtures shall be segregated with identification, category wise such as “Ordinary”/”Increased Safety”/”Flameproof” etc., ensuring these do not get mixed up. 7.0

NEWLY EQUIPMENT

RECEIVED

The preservative treatment required for new and old repaired/reconditioned equipment in storage is not different, except for the following additional

vii)

The Silicagel dehumidifiers, wherever provided, should be periodically examined and if there is discolouration due to absorption of moisture, these should be reactivated or replaced.

viii)

Wherever anticondensation spaceheaters are provided, these should be switched ON through thermostatic control, and monitored to prevent excessive rise of temperature (The body temperature shall be maintained around 10oC above ambient).

ix)

It should be ensured that the end sealing of cables is in tact.

x)

The equipment/components which are constructed out of ceramics (such as glass, stoneware, earthenware, porcelain, silica etc.) should be handled/stored carefully, to avoid cracks/damages.

xi)

Whenever transformer is received with Nitrogen blanketing the same should be maintained in storage.

xii)

Transformers should be provided with stoppers to the wheels for preventing likely lateral movement.

xiii)

While lifting, any equipment, alllugs and shackles provided on the equipment only should be used (to avoid any unbalance while lifting).

xiv)

Where it is not possible to unload the transformer directly on a foundation, it should be unloaded on a properly built wooden sleeper platform. (At no instance, a transformer should be kept on bare ground).

xv)

Loose accessories of the transformer/switchgear should be tagged for easy identification.

xvi)

Winding wires for motors and other equipment should be kept in original packing and stored in racks, taking care to avoid damages. “Slilcagel” to absorb moisture should be provided and the same should be inspected periodically and replaced as required.

xvii)

Spare ready coils shall be provided as per manufacturer’s recommendation.

xviii) Shelf life of the resin and tape should be taken care while stocking the cable joining and termination kits. Such of those joining kits in existence beyond their shelf life, should be destroyed. xix)

8.0

The manufacturer’s recommendations for preservation of newly supplied equipment, prior to their erection and commissioning should be followed.

REFERENCES

The following Codes, Standards and Publications have either been referred to or used in the preparation of this document and the same shall be read in conjunction with this document: *

OISD-STD-137, OISD-RP147, OISD-RP-148

*

IS:335

*

IS:10028

*

IS:1255

*

IS:1554

*

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