revised specification for 3500 kva transformer-for ......iss -2026/1977 specification for power...

Signature And seal of Bidder of 27

Installed

SCHEDULE – A

SR.

NO.

DESCRIPTION OF MATERIAL QUANTITY – Nos.

Tender Offered

1. Power Transformer 3500KVA, 11 KV / 6.9KV Voltage Ratio,

183 A / 293 A current ratio, YNyn0 vector, ON cooling , with

NGR on LV side. Make: Ashok / Apex / Voltamp/ BHEL/TELK/

Crompton Greaves /ABB/ EASSUN/ AREVA T&D. The detail

specifications are as per GTP (Schedule –B1) (Section I to V).

The transformer is required for CCPP Unit-2 black start facility

at Dhuvaran.

1 No.

Type : 3 phase, oil filled normal continuous rating (KVA) : 3500 KVA

No load voltage ratio (KV) : 11 / 6.9 KV

Winding material : Copper.

Connection (A) High voltage : Star (Neutral Brought out)

(B) Low voltage : Star (Neutral Brought out)

Vector Group : YNyn0

Tapping on H.V. Side for giving voltage variation of HV : + 7.5% to – 7.5% in steps of 2.5%

Type of Tap changer: OFF LOAD Circuit tap changer.

Temperature rise of oil / WDG, by thermometers resistance method over specified Ambient

temp. of 50 Degree Cent.

At Principal Tap: 40/45 Degree cent.

No load loss at rated current at 75 °C at Normal Tap : - 3.5 KW Max. (Tol. As per IS)

Load loss at rated current at 75 °C at Normal Tap : - 20 KW Max. (Tol. As per IS)

Terminal (HV/LV/Orientation): Cable Box/Cable Box / 180 Degree

Impedance at rated current at 75 Degree: 6.25 % as per (Tol. As per IS)

Fitting : Rating and diagram plate, Terminal Marketing Plate, lifting and jacking lugs, Silica gel

breather, Bottom drain cum filter valve, Top filter valve, Thermometer pocket,

Conservator with oil filling hole and drum plug, flat rollers, PRV, oil temperature

indicator, winding temperature indicator, Buchholz relay with 2 Nos. shut-off valves,

Magnetic oil level gauge, Marshalling Box.

Paint: Epoxy as per I.S.

1. The estimated cost of this tender is Rs..31,72,000.00

2. Cost of the Tender Documents is Rs. 1,000/- which is non refundable.

Details of Tender fees are as under:

Demand Draft No. ___________________ dtd. ________________

of Bank ___________________________________ Rs. For Rs. 1,000.00

3 EMD amount to be paid is Rs. _____________. Details of the EMD are as under:

Demand Draft No. _______________________ dtd. ________________ of

Bank ___________________________________ Rs. For _________


Installed

4 Delivery Period: The delivery schedule of the materials against this tender shall be

commencing within one month and completed in one quarter thereafter. The delivery period

will be reckoned from the date of receipt of order. The inspected material is to be

dispatched within 15 days from the date of Dispatch Instructions.

5 Bidder shall have to arrange for inspections and routine tests on subject transformer and

terminal connectors at their works in presence of GSECL Engineer.

6 The tenderers are requested to clarify whether they have laboratory having facility to carry

out routine tests as mentioned in GTP.

7 The Bidder shall furnish four sets of the type test reports for the type and Design of

transformer offered by him along with the offer. The Type Test report shall not be older

then 5 (five) years prior to the date of opening of the Bid, otherwise the offer will not be

considered.

8 Guarantee: - The Guarantee from the date of supply shall be as per Clause No.46 of the

Commercial Terms & Conditions for 60 months as applicable.

9 Performance Guarantee:- The performance Guarantee shall be as per Clause No. 47 of

Commercial Terms & conditions, amounting to 10% of the order value ( End Cost) shall be

paid either in form of Bank Guarantee or in Cash / Demand Draft by you, immediately on

commencing the supply for satisfactory performance of the materials.

10 EMD cover must contain the following documents (a, b & c) :

(a) Details & Documents as per clause No. 11 (Commercial terms and conditions) of this

tender. However company would accept B.G. issued by all Public Sector Banks &

private Banks like IDBI Bank, UTI Bank, HDFC Bank & ICICI Bank only.

(b) List of Orders executed during last three (3) years from the date of publication of

tender notice (including supplied made to erstwhile GEB) for the tendered items.

(c) Vender Registration Certificate: Irrespective of the bidder being Regular supplier or

new entrant to the GSECL, the copy of valid vendor registration certificate must be

enclosed otherwise the offer is likely to be rejected.

10. In case Corporation finds that there is an attempt of cartel in the prices. Corporation

reserves the right to consider or reject any or all the parties offer without assigning any

reason thereof.

11 Corporation reserves the right to terminate the contract at any time, without assigning any

reason, whatsoever, by giving a notice period of one month from the date of notice of

termination of the contract. Suppliers will not be entitled for any compensation/ damages /

losses, whatsoever, on account of such termination of the contract. Other text portion of

Clause No. 57 – Termination Of Contract will also be applicable.


Installed

SCHEDULE – B1

QUALIFYING REQUIREMENT FOR BIDDERS FOR 11/6.9 KV , 3500 KVA Transformer for GSECL – Dhuvaran CCPP 1. Bidder should be a manufacturer, who have designed, manufactured 11 KV Class

transformers and successfully tested as per IS/IEC or any equivalent standard, which are in successful operation for not less than 3 years any where as on the date of bid opening.

2. Bidders not meeting the requirements at 1 above but where the manufacturer has

designed, manufactured, tested and supplied similar equipment of at least the lowest rating specified and which are in successful operation on the date of bid opening can also participate provided they have valid on going collaboration with a manufacturer, who has at least 10 years experience in the design, manufacture and testing of the equipment of the type and class specified, which have been in satisfactory service for a period of at least 7 years. In such an event, the bidder shall furnish, along with his bid, documentary evidence for the same and an undertaking from the collaborator accepting joint and several liability all obligations under the contract.

3. Bidder shall invariably furnish documentary evidence (client’s certificate) in support of the satisfactory operation of the equipment as specified above. 4. Further, the Bidder shall furnish, with his bid type, test reports as per IS/IEC or

any equivalent standard of the equipment being offered. However, the type test reports of the collaborator for equipment similar to the type as offered, would be considered for the purpose of these qualifying requirements.

5. The manufacturer shall have adequate design, infrastructure and manufacturing

facilities and capacity and procedures including quality control. 6. Notwithstanding anything stated above, the owner reserves the right to access

bidder’s capability and capacity to perform the contract should circumstances warrant such an assessment in the overall interest of the owner.


Installed

SECTION – I

TECHNICAL SPECIFICATION FOR OUTDOOR TYPE POWER TRANSFORMER OF 11 KV/6.9 KV CLASS, 3500 KVA

GENERAL REQUIREMENTS FOR TRANSFORMER :

1.0 SCOPE: This specification covers, engineering, manufacture, assembly, stage

testing, and inspection and testing before supply and delivery at site of oil immersed, naturally cooled 3 phase 11 kV/6.9KV Transformer for outdoor use along with commissioning at site.

1.1 It is not the intent to specify completely herein all the details of the design and construction of

equipment. However the equipment shall conform in all respects to high standards of engineering, design and workmanship and shall be capable of performing in continuous commercial operation up to the Bidder’s guarantee, in a manner acceptable to the purchaser, who will interpret the meanings of drawings and specification and shall have the power to reject any work or material which, in his judgment is not in accordance therewith. The offered equipment shall be complete with all components necessary for their effective and trouble free operation. Such, components shall be deemed to be within the scope of Bidder’s supply irrespective of whether those are specifically brought out in this specification and / or the commercial order or not.

1.2 Standard Ratings: The Standard Ratings shall be 3500 KVA.

2.0 CODES AND STANDARDS 2.1 The design, manufacture and performance of equipment shall comply with all currently applicable

statues, regulations and safety codes in the locality where the equipment will be installed. Nothing in this specification shall be construed to relieve vendor of this responsibility.

2.2 Material conforming to other internationally accepted standards, which ensure equal or higher

quality than the standards mentioned above, would also be acceptable. In case the Bidders who wish to offer material conforming to the other standards, salient points of difference between the standards adopted and the specific standards shall be clearly brought out in relevant schedule. Four copies of such standards with authentic English translations shall be furnished along with the offer.

The materials shall conform in all respects to the relevant Indian / International Standard Specification, with latest amendments thereof, some of them are listed below:

Indian Standard Title International & Internationally recognised standard

ISS -2026/1977 Specification for Power Transformer IEC 76

ISS - 1180 Outdoor distribution Transformer upto and including 100 kVA

IS 12444 Specification for Copper wire rod ASTM B-49

ISS -3347/1967 Specification for porcelain Transformer bushing

DIN 42531,23,3

ISS-335/1983 Specification for Transformer Oil BS 148, D-1473, D-1533- 1934 IEC Pub 296-1969

ISS 5/1961 Specification for colors for ready mixed paints

ISS - 2099/1973 Specification for High Voltage Porcelain bushings

ISS - 7421/1974 Specification for Low Voltage bushings

ISS - 3347 Specification for Outdoor Bushings DIN 42531 to 33


Installed

ISS - 5484 Specification for Al Wire rods ASTM B - 233

ISS - 9335 Specification for Insulating Kraft Paper IEC 554

ISS - 1576 Specification for Insulating Press Board IEC 641

ISS- 6600/1972 Guide for loading of oil Immersed Transformers

IEC 76

ISS-649 Testing of Steel Sheets & Strips For Magnetic circuits

ISS-6162(Part-I&II) Paper covered Aluminum Conductor

ISS-10028 Installation , Maintenance Of Transformers

ISS-4257 Dimension for clamping arrangement for bushings (for porcelain and metal parts)

ISS- 6160 Rectangular conductors for electrical machine

ISS- 3401 Silica gel

ISS-1866 Code of practice for maintenance & supervision of Mineral insulating oil in equipment

IS : 3639 Fitting and Accessories for power Transformers

IS : 335 Insulating oil for transformers and Swichgear.

3.0 OPERATIONAL REQUIREMENTS 3.1 VOLTAGE AND FREQUENCY VARIATIONS

a) Transformers shall operate without injurious heating, on any tap, under the following conditions, provided increase in voltage is not accompanied by reduction in frequency :

i) At rated KVA, with voltage variation of ± 10% of the voltage corresponding to the particular tap.

ii) At rated current, with 105% rated voltage. 3.2 OPERATION TH COOLING EQUIPMENT OUTAGE

Starting from hot conditions, transformers shall be capable of operating, without exceeding permissible temperature rises and with all forced cooling out of operation, under the following conditions : i) At rated voltage and frequency for not less than 1 – hour without load current. ii) At rated KVA for not less than 10 – minutes.

3.3 OPERATION UNDER OVERLOADS It shall be possible to operate transformer as per loading guide IS: 6600 up to overloads of

150%. There shall be no limitations imposed by bushings, tap changers, auxiliary equipment etc. to meet this requirement.

4.0 CONSTRUCTIONAL FEATURES :

MATERIAL - CRGO/ AMORPHOUS METAL :

CRGO Material: The core shall be of NEW high grade cold rolled grain annealed steel lamination having low loss and good grain properties, coated with hot oil proof insulation, bolted together and to the frames firmly to prevent vibration or noise. The complete design of core must ensure permanency of the core losses with continuous working of the transformers. The value of the maximum flux density allowed in the design and grade of lamination used shall be clearly stated in the offer. Core Clamping for CRGO : MS channel shall be used on top and bottom Core Channel on LV side to be reinforced at equidistance, if holes / cutting is done for LT lead in order to avoid bending of channel. MS Channels shall be painted with oil-resistant paint. The transformers core shall be suitable for over fluxing (due to combined effect of voltage and frequency) upto 12.5% without injurious heating at full load conditions and shall not get saturated. The Bidder shall furnish necessary design data in support of this situation. The nominal flux density in any part of the core shall not exceed 1.65 Tesla at 1.0 p.u.voltage The vendor shall furnish necessary design data in support of this stipulation. No load current shall not exceed 2% of full load current and will be measured by energizing the transformer at 6.9 KV, 50 c/s on the secondary. Increase of voltage of 6.9 KV by 12.5% shall not increase the no load current by Max. 6% of full load current. Test for magnetic balance by


Installed

connecting the LV phase by phase to rated phase voltage and measurement of an, bn, cn voltage will be carried out. Clamping and Tie-rods shall be made from HT steel & shall be parkarised. AMORPHOUS METAL: The core shall be high quality amorphous ribbons having very low loss formed into wound cores of rectangular shape, bolted together to the frames firmly to prevent vibration or noise. The complete design of core must ensure permanency of the core loss with continuous working of the transformers. The value of the flux density allowed in the design shall be clearly stated in the offer. Curve showing the properties of the metal shall be attached with the offer. Core Clamping for Amorphous metal Transformers Core clamping shall be with top and bottom U-shaped core clamps made of sheet steel clamped HT steel tie rods for efficient clamping. MS core clamps shall be painted with varnish or oil-resistant paint. MS rods shall be used as tie rods. Suitable provision shall be made in the bottom core clamp / bottom plate of the transformer to arrest movement of the active part. NOTE: "Equal weightage shall be given to the transformers with Amorphous metal core & CRGO ".

4.1.1 Similar parts, particularly removable ones, shall be interchangeable. 4.1.2 Screws, studs, nuts and bolts shall be as per Indian Standards. 4.1.3 Nuts, bolts, pins used inside the transformers and tap changer compartments shall be locked. 4.1.4 Exposed parts shall not leave pockets where water can collect. 4.1.5 Internal design of transformer shall ensure that air is not trapped in any location. 4.1.6 Facility shall be provided for lubrication of bearings and mechanisms. Mechanisms shall be

constructed of non- corrodible materials. 4.1.7 Materials in contact with oil shall be such as not to contribute to the formation of acid in oil. Surface

in contact with oil shall not be galvanized or cadmium plated. 4.1.8 Labels, indelibly marked, shall be provided for all accessories like relays, switches, fans, current

transformers etc. 4.2 CORE 4.2.1 The magnetic circuit shall be of ‘core type’ construction. The core shall be built out of high grade,

non-ageing, low loss and high permeability, cold rolled grain oriented silicon steel laminations. 4.2.2 After being sheared the laminations shall be treated to remove all burrs. Both sides of the

laminations and the cut edges shall be treated with carline insulation 4.2.3 The finally assembled core shall be free from distortion. It shall be rigidly clamped to ensure

adequate mechanical strength and to prevent vibrations during operations. 4.2.4 The core clamping structure shall be designed to minimize eddy current loss. 4.2.5 The core shall be provided with lugs suitable for lifting the complete core and coil assembly. 4.2.6 The core and coils assembly shall be so fixed in the tank that shifting will not occur during

transport or short circuits. 4.2.7 All steel sections used for supporting the core shall be thoroughly sand-blasted, after cutting

drilling and welding.

4.3 INTERNAL EARTHING 4.3.1 All internal metal parts of the transformers, with the exception of individual laminations, core bolts

and their individual clamping plates; shall be earthed. Core clamps and core bolts shall be insulated from the core by class B insulation unless other insulation is approved by Purchaser.

4.3.2 The top clamping structure shall be connected to the tank by a copper strap. The bottom clamping structure shall be earthed by one or more of the following methods.

a) By connection through vertical tie-rods to the top structure. b) By direct metal to metal contact with the tank base. c) By a connection to the top structure on the same side of the core as the main earth connection to

the tank. 4.3.3 The magnetic circuit shall be connected to the clamping structure at one point only, through a link

placed in or accessible position beneath an inspection opening on the tank cover. The link shall be on the same side of the core as the main earth connection in 4.3.2 above.

4.3.4 When the magnetic circuit is sub-divided by oil ducts or insulated barriers above 0.25 mm thick, tinned copper strip bridging pieces shall be inserted to maintain electrical continuity between packets.

4.3.5 Coil clamping rings of metal at earth potential, shall be connected to the adjacent core clamping structure on the same side as the main earth connection in 4.3.2 above.


Installed

5.0 WINDINGS (Uniform Winding) Materials: - Only Super enamel covered copper Conductor or Double paper covered

copper conductor shall be used for 11 KV , 3500 KVA. 5.1 Windings shall be subjected to a shrinking and seasoning process, so that no further shrinkage

occurs during service. Adjustable devices shall be provided for taking up possible shrinkage in service.

5.2 Coils shall be supported at frequent intervals by means of wedge type insulation spacers permanently secured in place and arranged to ensure proper oil circulation. To ensure permanent tightness of winding assembly, the insulation spacers shall be dried and compressed at high pressure before use.

5.3 Windings shall not contain sharp bends which might damage the insulation or produce high dielectric stresses. No strip conductor wound on edge shall have width exceeding six times the thickness.

5.4 Materials used in the insulation and assembly of the windings shall be insoluble, non-catalytic and chemically inactive in the hot transformer oil, and shall not soften or be otherwise affected under the operating conditions.

5.5 All threaded connections shall be locked. Leads from the winding to the terminal board and bushings shall be rigidly supported to prevent injury from vibration. Guide tubes shall be used where practicable.

5.6 Windings and connections shall be braced to withstand shocks during transport or short circuits. 5.7 Coil clamping rings shall be steel or of a suitable insulating material built from slat laminations. 5.8 Permanent current carrying joints in the windings and leads shall be welded or brazed, clamping

bolts for current carrying parts inside oil shall be made of oil resistant material which shall not be affected by acidity in the oil, steel bolts, if used, shall be suitably treated.

5.9 Terminals of all windings including unloaded stabilizing windings shall be brought out of the tank through bushings for external connections.

5.9.1 Windings shall be of copper unless specifically approved by the purchaser.

6.0 INSULATION MATERIAL :

a) Material: Electrical grade insulation Kraft Paper of standard make or better material subject to approval of the purchaser. Pressboard of standard make or better material subject to approval of purchaser.

b) All spacers, axial wedges / runners used in windings shall be made of pre-compressed

Pressboard−solid, conforming to type B 3.1 of IEC 641-3-2. In case of cross-over coil winding of HV all spacers shall be properly sheared and dovetail punched to ensure proper locking. All axial wedges / runners shall be properly milled to dovetail shape so that they pass through the designed spacers freely. Insulation shearing, cutting, milling and punching operations shall be carried out in such a way, that there should not be any burr and dimensional variations.

7.0 TANK 7.1 Tank shall be made from good commercial grade low carbon steel and shall be of welded

construction 7.2 Tank shall be designed to permit lifting, by crane or jacks, of the complete transformer assembly

filled with oil. 7.3 Tank shall be braced to withstand full vacuum of 760 mm of mercury and internal pressures during

normal and abnormal condition such as short circuit inside the transformer. (See also pressure test specified in Section 19.1.(e))

7.4 Suitable guides shall be provided in the tank for positioning the core and coil assembly. 7.5 Adequate space shall be provided at the bottom of the tank for collection of sediment. 7.6 The transformer base shall be designed to permit skidding of the complete transformer unit in any

direction, when using plates or rails. The under base shall be detachable unless transport facilities permit a fixed base.

7.7 The transformer top shall be provided with a detachable cover with a bolted flanged gasket joint. Lifting lugs shall be provided for removing the cover. The surface of the cover shall be suitably sloped so that it does not retain rain water.

7.8 When specified, the tank shall have an oil-tight bolted flanged gasket joint near the base of the transformer, so that the tank can be lifted off to have access to core and coils. Suitable projecting guides shall be provided on the core and coil assembly, to facilitate removal of the tank without lifting the coils. It shall be feasible to weld-off the flanged joint at the base in case of oil leakages.

7.9 Necessary measures shall be adopted like increased clearances and separate aluminum shields to minimize eddy current losses in large capacity and high impedance transformers.


Installed

7.10 The material used for gaskets shall be cork-neoprene or approved equivalent. Gasket joints for tank and manhole covers, bushings and other bolted attachments shall be so designed that the gasket will not be exposed to the weather. Stops to prevent crushing shall be provided for compressible gaskets.

8.0 UNDER CARRIAGE The under carriage of the transformer shall be provided with detachable steel flanged wheels of flat rollers as specified. Flanged wheels shall be spaced to allow specified rail gauge. Wheels shall be provided with suitable bearings which will resist rust and corrosion and shall be equipped with fittings for lubrications. Unless otherwise approved, it shall be possible to swivel the wheels or rollers in two directions, at right angles to or parallel to the main axis of the transformer, thereby permitting movement in two directions. The wheels or rollers will be swiveled after jacking the transformer and they shall be lockable in the two positions.

9.0 OIL Transformer and associated oil filled equipment shall be supplied with first filling of oil plus 10% extra in non returnable drums. The oil shall confirm to IS: 335. No inhibitors shall be used in the oil. The make of oil shall be subject to Purchaser’s approval.

10.0 BUSHINGS 10.1 Bushings for voltages of 66 KV and above shall be of the oil filled condenser type and shall

preferably be of the draw lead type to facilitate removal. For voltage below 66 KV solid porcelain or oil communicating type bushings may be used.

10.2 Condenser type bushings shall be provided with – a) Oil level gauge. b) Oil filling plug and drain valve if not hermetically sealed. c) Taps for capacitance test. d) Steers rings and lower end shields. 10.3 11 KV bushings shall be used for 6.9 KV and 3.3 KV service. 10.4 When bushings have an under-oil end of re-entrant form, pull through lead shall be fitted with a

gas bubble deflector. 10.5 Oil for the bushings shall be same as transformer oil. 10.6 Bushings rated for 400A and above shall have non-ferrous flanges and hardware.

11.0 CABLE BOXES AND DISCONNECTING CHAMBERS. 11.1 When connection is by cable, unless otherwise approved, disconnecting chamber shall be

provided for disconnecting and moving away the transformer without unsealing the cables or draining oil from the main tank, leaving the cable box or chamber. Behind on Purchaser’s external supports.

11.2 Cable boxes and sealing ends shall be complete with jointing materials, compound and all other accessories including wiping glands, armour, earthing clamps, and tinned copper crimping type solder less lugs shall be in scope of supply.

11.3 The cable box shall have all standard facilities including fitting and drain plugs, relief vent, level glass and body earth terminals.

11.4 The disconnecting chamber shall preferably be air insulated. If oil insulated, the oil shall be segregated from transformer tank oil or cable box oil. Bushings, oil filling and drain plugs, relief vent, level glass, and removable cover shall be provided for the disconnecting chamber. Plates through which high current carrying conductors pass, shall be non-magnetic unless otherwise approved by Purchaser.

11.5 Phase to phase and phase to ground clearances within the chamber shall be subject to Purchaser’s approval.

12.0 TRANSFORMER COOLING EQUIPMENTS 12.1 BUILT-ON RADIATORS Unless otherwise approved, tank mounted radiators shall be of the detachable type with bolted flanged

connections. The following accessories shall be provided for each radiator : a) Shut off valves and blanking plates on transformer tank at each point of connection. b) Top and bottom shut off valves and blanking plates on each radiator. c) Lifting lugs. d) Top oil filling hole with cap. e) Air release plug at top. f) Oil drain plug at bottom


Installed

13.0 TAP CHANGING GEAR 13.1 OFF CIRCUIT TAP CHANGING GEAR The off circuit tap changer shall be opera-table by means of an operating handle brought outside

the tank. It shall be equipped with an indicating device to show the tap in user and shall be provided with a locking arrangement to lock the switch in position. The tapping shall be provided on HV side to suit variation in voltage on HV side. The rotary tap changing switch shall be of approved design ( design details and drawings to be supplied with the offer ) suitable for external manual operation on off load. Cast indicating plate with switch with a movable pointer to be provided to clearly show tap position number.

14.0 CONTROL CABINETS. OFFLOAD TC local control cabinet, Marshalling box and cooler Control cabinet. Local Temperature indicator meter for OTI & WTI

13.1 Execution Outdoor IP 54 as per IS:2147 13.2 Mounting Tank mounted or mounted on a separate

foundation. 13.3 Wiring All alarm and trip circuits shall be wired

for auxiliary DC Supply as specified.

General Specification In accordance with enclosed Specification. Special requirement Bottom shall be at least 600 mm from floor level. Top Surface shall be sloped. Indicating lamps and meters Shall be covered by a glass Window.

15.0 FITTINGS AND ACCESSORIES

The following fittings and accessories shall be provided: 15.1 Inspection manhole(s) with cover(s) on the top cover of the transformer. 15.2 Lifting lugs or eyes for lifting of fully assembled transformer by crane. 15.3 Jacking pads, at least four in number, at suitable height, for lifting the complete transformer filled

with oil . 15.4 Lifting arrangement for core and coils. 15.5 Hauling eyes on each face of the transformer. 15.6 Skids at the bottom of the transformer when specified 15.7 Earthing pads: Two earthing pads of copper or other no corrodible material on transformer tank

together with clamp type terminals suitable for Purchaser's earthing conductors. Suitable earthing terminals on cable boxes and separately mounted radiator banks.

15.8 Neutral earthing bar of copper of specified section installed from the neutral bushing to ground level suitably supported along its run on porcelain insulators, together with clamping arrangements at neutral bushing and for to Purchaser’s earth conductors.

The NGR of 3500 KVA X'mer for 6.9 KV side is required. The specification as below. a) Rated voltage - 6.9 KV b) Rated current - 400 A c) Rated duty - 10 Sec d) Rated Resistance - 9.96 + 10 % e) Temp. rise - 375° over 50° C amb. f) Service - Out door g) IP 43 as per IS-2147

15.9 Terminal marking and rating plates shall be as per IS: 2026.


Installed

15.10 Conservator (for transformer ratings as per IS: 2026) : The conservator shall be sufficient volume to maintain the oil seal from the minimum

ambient temperature of - 50°C, with oil level varying within the minimum and maximum visible levels. The conservator shall be provided with the following accessories :

a) Filling plug, sump and drain valve. b) 150 mm diameter magnetic type oil level gauge with low oil level alarm contacts or a

prismatic oil sight gauge both provided with markings for minimum oil level and oil

level at 30°C as specified. c) A bolted cover for cleaning. d) Valve for shutting off oil to the transformer. e) Weather proof de hydrating breather with silica gel and oil seal to eliminate constant

contact with the atmosphere, mounted at a level of about 1400 mm above ground level.

15.11 VALVES The following valves shall be included on the transformer tank.

15.11.1 Main tank drain valve with flanged or threaded connection. 15.11.2 Top filtering valve with plug located on the same side as the main drain valve. 15.11.3 Bottoms filter connection with plug to drain oil from the lowest part of the tank. This

connection shall not be tapped through the bottom of the transformer. 15.11.4 Oil sampling devices at top and bottom of the main tank. These shall be distinct from other

valves. 15.11.5 Adequate number of air relief vents. 15.11.6 Two plugged pipe outlets at top for applying vacuum. All valve opening shall be plugged or

blank flanged. 15.11.7 Valves for the cooler systems are indicated in the respective sections. These valves shall

be lockable in closed or open positions and shall be provided with an indicator to show position of the valve.

15.12 Pressure Relief Devices: A pressure relief vent mounted on the tank shall be provided

for relieving pressure within the transformers. It shall operate for pressure less than the hydraulic test pressure for the tank.

15.13 GAS AND OIL ACTUATED RELAY (BUCCHOLZ RELAY)

A double float type Buccholz relay as per IS: 3637/8 shall be provided whenever called . All gas evolved in the transformer shall collect in this relay. The relay shall be provided with a test cock suitable for a flexible pipe connection for checking its operation. A copper tube shall be connected from the gas collector to a valve located about 1.25 M above ground level to facilitate sampling with the transformer in service. The device shall be provided with two electrically independent ungrounded contacts, one for alarm on gas accumulation and the other for tripping on sudden rise of pressure.

15.14 TEMPERATURE INDICATORS 15.14.1 OIL TEMPERATURE INDICATOR

Transformer shall be provided with a 150 mm dial type temperature indicator for top oil temperature indication. The indicator shall have adjustable, electrically independent ungrounded alarm and trip contacts, maximum reading points and resetting device. (Additionally Electronic Temperature indicator with Alarm & Trip settings equipped with suitable RTD shall be provided so that the temperature can be shown on breaker panel at Remote end approx. 800 Mtr away.-excluding cables)

15.14.2 WINDING TEMPERATURE INDICATOR A device for measuring the hot spot temperature of the winding shall be provided when called for It shall comprise of the following. Temperature sensing element. a) Image coil. b) Current transformer c) 150 mm dia local indicating instrument with two adjustable electrically independent

ungrounded contacts, two for winding temperature alarms. d) Calibration device. e) Automatic ambient temperature compensation. In addition to the above, the following

remote indication equipment shall be provided when called for . a) Analogue signal transmitter.


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b) Remote indicating, flush mounted instrument for mounting on breaker panel at Remote end approx. 800 Mtr away.-excluding cables.

16.0 RADIO INFLUENCE AND NOISE LEVEL 16.1 The transformers shall be designed with particular attention to the suppression of maximum

harmonic voltage especially the third and fifth, so as to minimize interference with communication circuits.

16.2 The noise level when energized at normal voltage and frequency with fans and pumps running shall not exceed 80 db when measured under standard conditions.

17.0 PAINTING 17.1 The interior of all transformer tanks and other oil filled chambers and internal structural steel

work shall be cleaned of all scale and dust by shot-blasting unless otherwise approved. These surfaces shall be painted with not less than two coats of heat resistant, oil insoluble and insulating varnish. Steel surfaces exposed to the weather shall be thoroughly cleaned and applied a priming coat of zinc chromate. The second coat shall be of an oil and weather resistant nature, preferably of distinct colour from the prime and finish coats. The final coat shall be of a glossy oil and weather resisting non fading paint of specified shade -631.

17.2 All exposed bolts, nuts and washers shall be of galvanized steel unless otherwise approved. 17.3 Metal parts not accessible for painting shall be made of corrosion-resistant material. Machined

finished and bright surfaces shall be coated with a suitable compound and wrapped. 17.4 Interior surfaces of mechanism chambers and knocks shall receive three coats of paint after

proper cleaning the final coat shall be of a light-coloured anti condensation paint.

18.0 TESTS Transformers shall be completely assembled at works to ascertain that all parts fit correctly. The equipment offered shall be fully type tested by the bidder or his collaborator as per the relevant standards. The type test must have been conducted on a transformer of same design. The Bidder shall furnish four sets of type test reports along with the offer. Offers without type test reports will be treated as Non-responsive. b) Special tests other than type and routine tests, as agreed between purchaser and Bidder shall also be carried out as per the relevant standards. c) The requirements of site tests are also given in this clause.

d) The test certificates for all routine and type tests for the transformers and also for the bushings and transformer oil shall be submitted with the bid.

18.1 ROUTINE TEST

All the Routine tests as per IS shall be performed on transformers. The following additional points may be noted: a) Resistance of winding shall be measured at principal and the two extreme taps. b) Impedance voltage shall be measured at principal and the two extreme taps. c) No load loss and exciting current shall be measured at rated frequency at 100% and

110% rated voltage. These tests shall be done before and after impulse tests if the later are specified. Exciting current shall be measured on each phase and recorded.

d) No load loss and exciting current shall be measured and recorded with 415V, 3 phase 50 Hz input on LV side (assuming LV is rated higher than 415V).

e) Oil Pressure Test: All oil filled compartments shall be filled with transformer oil and

subjected to a pressure of 0.35 Kg/cm2 above the pressure that would obtain under

normal conditions with full head of oil. The pressure shall be maintained for 12 hours during which time no oil leakage shall occur. When heat run test is specified the oil pressure test shall be performed immediately after the heat run. Otherwise the test may be performed at ambient temperature.

18.2 TYPE TESTS

Vendor shall quote extra itemized prices for performing the following tests: a) Impulse Test: This shall include chopped wave test. Itemized prices shall be given for :

i) Impulse test on one leg (HV & LV) of the transformer. ii) Impulse test on all legs of the transformer.

b) Temperature rise test.


Installed

c) Measurement of zero-sequence impedance. d) Measurement of acoustic noise level.

e) Measurement of tan δ and capacitance of each winding to earth (with all other windings grounded and between all windings (connect together) to earth.

f) Short circuit impedance of each limb of the transformer with single phase voltage from both H.T and L.T. sides. This is required to check mechanical displacement between windings.

g) Partial discharge test h) Switching surge withstand test

18.3 TESTS AT SITE: The purchaser reserves the right to conduct all tests on Transformer after

arrival at site and the manufacturer shall guarantee test certificate figures under actual service conditions.

18.4 AUXILIARY EQUIPMENT All auxiliary equipment shall be tested as per the relevant IS. Test certificates shall be

submitted for bought out items. High voltage withstand test shall be performed on auxiliary equipment and wiring after complete assembly.

18.5 TEST REPORTS

Four copies of preliminary test results shall be submitted for Purchaser’s approval before dispatch of transformer. Additional bound copies as per enclosed distribution schedule of complete test results including all tests on transformer, auxiliaries, bushings and current transformer characteristics shall be furnished with the transformer. Also, test report of transformer oil should be submitted.

19.0 LOSSES 19.1 The design of the transformer should be such as to have minimum possible No load and load

losses as per design criteria of the rating of the transformer. 19.2 The bidder should guarantee individual No load loss and load loss without any positive

tolerance. The bidder should also guarantee the total losses at 50% and 100% load condition (50% and 100% of rated KVA rating at rated voltage and frequency and at 75 deg centigrade without any positive tolerance.

19.3 For the purpose of evaluation of the bids for the transformer, Capitalized cost of transformer shall be worked out. The offers will be compared on capitalized cost of the transformer

19.4 For the purpose of evaluation of bids, the quoted load losses and iron losses shall be increased by 10% to reflect + 10% tolerance as permitted by ISS. NOTE:- The tolerance specified herein is for total losses i.e. No load losses and load losses. The tolerance on individual losses shall be as per ISS.

19.5 Transformer with losses specified by bidder will be capitalized during bid evaluation worked out by following formula

Capitalized cost of the Transformer = IC + (A x Wi) + (B x Wc)

Where IC= Initial cost of Transformer (without tax) as quoted by the Bidder A factor = cost of No Load losses in Rs / Watt = 276.75 Rs./Watt B factor = cost of Load Losses in Rs/Watt = 89.94 Rs./Watt Wi = No load losses quoted by the manufacturer in watt Wc = Load losses quoted by the manufacturer in watt 19.6 Penalty for Non Performance In the case of order if the figures of losses measured during tests are found to be higher than the figures guaranteed plus 10% tolerance allowable, the transformer at the option of the board will be rejected or accepted with the reduction in price at under

For, No Load Losses: @ Rs. 553=00 Rs / Watt. Load losses at 100% Load: @ Rs. 180=00 Rs/Watt


Installed

20.0 REJECTION Purchaser may reject any transformer if during tests or service any of the following conditions

arise : 20.1 No load loss exceeds the guaranteed value by 20% or more. 20.2 Load loss exceeds the guaranteed value by 20% or more. 20.3 Impedance value exceeds the guaranteed value by ± 10% or more.

20.4 Oil or winding temperature rise exceeds the specified value by 5°C. 20.5 Transformer fails on impulse test. 20.6 Transformer fails on power frequency voltage withstand test. 20.7 Transformer is proved to have been manufactured not in accordance with the agreed

specification. 20.8 Purchaser reserves the right to retain the rejected transformer and take it in to service until the

Seller replaces, at no extra cost to Purchaser, the defective transformer by a new transformer. 20.9 Alternatively, the Seller shall repair or replace the transformer within a reasonable period to

Purchaser’s satisfaction at no extra cost to the Purchaser. 21.0 GUARANTEE FOR THE TRANSFORMERS; 1) Guarantee period shall be 60 months from the date of supply. 2) The supplier shall return guarantee failed transformers duly repaired and tested as per approved

GTP and tender specification within 30 days from the date of receipt at repair shop without any cost, failing which bank guarantee shall be encased without any notice and all business will be stopped with the said supplier at least for a period of 3 years.This clause itself shall be the notice to the supplier about encashment of Bank Gurantee incase of his failure to adhere to timelines & no separate notice will be survied.

3) After intimation of failure of transformer failed within guarantee period, Supplier will arrange for the

transport & insurance of guarantee period failed transformer to firm’s works (And back to GSECL site) at the cost of supplier. On receipt of guarantee period failed transformer at firm’s works, the external inspection will be carried out by the representative of GSECL not below the rank of Junior Engineer. The cost of any outer component damage not because of supplier’s fault and required to be provided will be reimbursed to the supplier as per the approved rate of GSECL on the strength of joint external inspection report. No. internal inspection of failed unit is to be carried out in presence of representative of GSECL. However, the supplier may prepare an internal inspection report of failed unit for his study and analysis. If required, such analysis shall be furnished to GSECL.

Testing of transformer will be done in presence of company’s Engineer to ensure losses as per

GTP, Transformer found with higher losses than GTP will not be accepted and cost thereof will be recovered. The new Transformers supplied in this circumstances must as per GTP submitted with tender and shall match the losses offered by the supplier as per Tender.

The testing of each G.P. failed transformers will be carried out for all acceptance test as per the

relevant standard where no load losses and load losses are also required t be maintained identical as per GTP attached

22.0 SPARES Bidder shall quote itemized prices for recommended spares, including the following: 22.1 Complete set of gaskets. 22.2 One bushing of each type. 22.3 Dial type temperature meter 22.4 Complete set of winding temperature indicating equipment. 23.0 INSPECTION: All tests and inspection shall be made at the place of manufacturer and unless other wise

especially agreed upon the manufacturer and the purchaser at the time of purchase. The manufacturer shall afford the inspector representing the purchaser all reasonable facilities, without charge to satisfy him that the material is being furnished in accordance with specification.

The manufacturer shall provide all services to establish and maintain quality of workman ship in

his works and that of his sub-contractors to ensure the mechanical / electrical performance of


Installed

components, compliance with drawings, identification and acceptability of all materials, parts and equipment as per latest quality standards of ISO 9000.

Along with the bid the manufacturer shall prepare Quality Assurance Plan identifying the various

stages of manufacture, quality checks performed at each stage and the Customer hold points. The document shall also furnish details of method of checking, inspection and acceptance standards / values and get the approval of purchaser or his representative before proceeding with manufacturing. However, purchaser or his representative shall have the right to review the inspection reports, quality checks and results of manufacturer’s in house inspection department which are not customer hold points and the manufacturer shall comply with the remarks made by purchaser or his representative on such reviews with regards to further testing, rectification or rejection etc. Manufacturer should submit the list of equipment for testing along with latest calibration certificates to the purchaser.

Purchaser shall have every right to appoint a third party inspection to carryout the inspection

process. The purchaser has the right to have the test carried out at his own cost by an independent agency wherever the dispute regarding the quality of supply. Purchaser has right to test 1% of the supply selected either from the stores or field to check the quality of the product. In case of any deviation purchaser have every right to reject the entire lot or penalize the manufacturer, which may leads to blacklisting among other things.

24.0 QUALITY ASSURANCE PLAN: 24.1 The Bidder shall invariably furnish following information along with his bid, failing which his bid

shall be liable for rejection. Information shall be separately given for individual type of equipment offered.

i. Statement giving list of important raw materials, names of sub-suppliers for the raw materials, list of standards according to which the raw materials are tested. List of tests normally carried out

on raw materials in the presence of Bidder’s representative, copies of test certificates. ii. Information and copies of test certificates as in (I) above in respect of bought out accessories. iii. List of manufacturing facilities available. iv. Level of automation achieved and list of areas where manual processing exists. v. List of areas in manufacturing process, where stage inspections are normally carried out for quality control and details of such tests and inspection. vi. List of testing equipment available with the bidder for final testing of equipment along with valid calibration reports shall be furnished with the bid. Manufacturer shall posses 0.1 class instruments for measurement of losses. vii. Quality Assurance Plan (QAP) with hold points for purchaser’s inspection as per Annexure. 24.2 The successful Bidder shall within 30 days of placement of order, submit following information to

the purchaser. i. List of raw materials as well as bought out accessories and the names of sub-suppliers selected from those furnished along with offer. ii. Type test certificates of the raw materials and bought out accessories. 24.3 The successful Bidder shall submit the routine test certificates of bought out accessories and

central excise passes for raw material at the time of routine testing. 25.0 PACKING & FORWARDING: 25.1 The packing shall be done as per the manufacturer’s standard practice. However, it should be ensured that the packing is such that, the material would not get damaged during transit by Rail / Road / Sea. 25.2 The making on each package shall be as per the relevant IS.


Installed

26.0 SCHEDULE: 26.1 The tenderer shall fill in the following Schedules mentioned in Section-V which from part of the

tender specification and offer. In schedule ‘A’ the specific values shall be furnished and only quoting of IS reference is not sufficient. If the schedule are not submitted duly filled in with the offer, the offer shall be liable for rejection.

Schedule ‘A’. Guaranteed Technical Particulars Schedule ‘B’ Schedule of Deviations from Specification. Schedule ‘C’. Schedule of Tenderer’s Experience. 26.2. All deviations from the specifications shall be brought out in the schedules of deviation (Schedules

‘B’). The discrepancies between the specification and the catalogues, literatures and indicative drawings which are subject to change, submitted as part of the offer, shall not be considered and representation in this regard will not be entertained. If it is observed that there are deviations in the offer in G.T.P. of elsewhere other than those specified in the deviation schedule ‘B’ then such deviations shall be treated as deviations.

26.3. For any deviation from the specification, which is not specifically brought out in the schedule of

deviations, the offer may be liable for rejection. The deviation brought out in the schedule shall be supported by authentic documents, standards and clarifications; otherwise the offer may be liable for rejection. GSECL at their discretion will decide regarding acceptance of deviation.

26.4. The tenderer shall submit the list of orders for similar type of equipments, executed of under

execution during the last three years, with full details in the schedule of Tender’s experience (Schedule ‘C’) to enable the purchaser to evaluate the tender.

27.0 DRAWINGS / DATA / DOCUMENTS TO BE SUBMITTED BY BIDDER ALONGWITH THE BID

As a minimum, the bidder shall furnish the following in two sets failing which the bids shall be rejected.

i) Typical general arrangement drawing of the equipment showing overall dimensions. ii) Typical schematic drawing in respect of equipments offered iii) Catalogues for equipment and fittings & accessories iv) Operation & Maintenance Manual. v) Schedules as per Section IV. vi) Quality assurance plan vii) Type test reports of similar rating equipment viii) Experience certificates of supply of identical types of equipment ix) List of sub-vendors for purchaser’s approval.

28.0 DRAWINGS / DATA / DOCUMENTS TO BE SUBMITTED BY SUCCESSFUL BIDDER

After issue of detailed purchase order, the successful bidder shall submit documents as mentioned in Section-V, for approval. In normal practice, the documents submitted for the approval will be commented upon or approved if in order, within 30 days from the date of receipt of the same.

Date: Signature. Name : Status.


Installed

SECTION – II

ADDITIONAL REQUIREMENTS AND TERMINAL DETAILS :

1.0 EQUIPMENT TO BE SUPPLIED : The 3500 kVA, 11000 / 6900 V auxiliary transformer with accessories shall be supplied.

ADDITIONAL REQUIREMENTS The following additional requirements shall be applicable for the auxiliary

Transformers covered under this specification:

OFF LOAD TAP CHANGER

The transformer shall be provided with OFF load tap changer with tap ranges .

TERMINAL DETAILS

2.2.1 HV line terminals : The cable box on HV side (11 KV) shall be suitable for terminating 11kV earthed grade aluminum 3C X 150 Sq. mm HT XLPE cable, -armoured, overall PVC sheathed

cable.

2.2.2 LV line terminals :

The cable box on LV side (6900V), shall be suitable for terminating 11kV earthed grade aluminum 3C X 300 Sq. mm HT XLPE cable, -armoured, overall PVC sheathed

cable.

2.2.3.LV neutral terminal : LV neutral terminal shall be equipped & connected with NGR.

2.2.4. Neutral Grounding Resistance:

The specifications of the NGR connected on 6.9 Kv side is as below. Rated voltage - 6.9 KV Rated current - 400 A Rated duty - 10 Sec Rated Resistance - 9.96 + 10 % Temp. rise - 375° over 50° C amb. Service - Out door IP 43 as per IS-2147

The cable box shall be suitable for terminating PVC insulated, aluminum conductor, Inner PVC sheathed, armoured, outer PVC sheathed, armoured, outer PVC sheathed cable.

Radiators shall be detachable type and preferably tank mounted.

Interconnecting cable and cable accessories for connection between transformer Marshalling box and all other electrical measuring, monitoring and protective devices mounted on the transformer shall be carried out by 650V/1100V grade PVC insulated, PVC sheathe, armored / unarmored cable run in GI conduits.



Installed

SECTION – III SPECIFIC TECHNICAL REQUIREMENTS :

SPECIFICATIONS:-

• GENERAL :- 1 Application / Designation Reference : As per specification 2 Quantity :- No : : 01 (one) 3 Installation :- Indoor / Outdoor : outdoor 4 Type :- Auto /2-WDG/3-WDG/Others : 2 Windings 5 Unit :- 3 Phase / Sigle Phase : : 3 Phase 6 Rating of Unit:- kVA : : 3500 7 Cooling :- ON/OB/OFB/ OFN/ OW/OFW : ON

• RATINGS :-

1 No load Voltages :- HV Winding (V) : 11000

LV Winding (V) : 6900 2 Frequency : (Hz) : 50 3 Rating for Each type of Cooling HV- kVA : 3500 LV- kVA : 3500 4 Percentage Impedance : HV- LV - % : 6.25 %

• WINDING CONNECTIONS : 1 Winding Connections (Vector Group ) : HV : YN O LV : yn o 2 Application / Direction of Power Flow : : Normally From HV to LV

• SYSTEM DATA : 1 System Voltages HV Normal / Highest kV : 11 / 12.0 KV LV Normal / Highest kV : 6.9 / 6.9 KV 2 Fault level HV system kA : 40 LV system kA : 42 3 System Neutral Earthing HV : Solidly grounded LV : Resistance grounded

• TRANSFORMER NEUTRAL : 1 Type of Earthing : HV : Solidly grounded LV : Resistance grounded

• WINDING INSULATION : 1. Whether, } HV : Fully insulated Fully insulated/ Graded insulated } LV : Fully insulated

• WINDING INSULATION TEST VOLTAGES : 1. Impulse Voltage withstand +ve & -ve (1.2/50 µs wave) : HV kVpeak ; 75 2. Power Frequency Voltage withstand (Dry&Wet) : HV kVrms : 28

LV kVrms : As per IS ( LV Bushing Rated for 11 KV)

• TEMPERATURE RISE :

1. Ambient Temp: Max. Ambient Air °C : 45

Max. Daily average Air °C : 35

Max. Yearly average Air °C : 32

2. Temp. Rise of oil by thermometer: °C : 40

3. Temp. Rise of winding by resistance ON cooling: °C : 45


Installed

• TAPPINGS : 1.Tapping on winding : HV/LV : HV 2 Whether ON LOAD / OFF LOAD : OFF LOAD 3. Total Tapping Range. : + 7 ½ To – 7 ½ 4 Step : % : 2 ½ 5 Capacity : Full/Reduced : Full

• TERMINAL BUSHINGS : Particulars HV line End LV Line End 1. Rated Voltage Class kV : 12 6.9 2. 1.2/ 50 µsec. Impulse Voltage With stand kV peak : 75 -- 3. One minute Power Frequency With stand (Dry & Wet) kV rms. : 28 As per IS ( LV Bushing Rated for 11 KV) 4. Minimum phase to phase clearance in Air mm : 350/ As per IS -- 5. Minimum phase to earth clearance in Air mm : 250 /As per IS -- 6. Minimum creep age distance (Total) mm : 300 /As per IS 7. Bushing CT required Yes/No : Yes (1) On R- Phase (A) for WTI of suitable CT ratio.(293/2.3 A), (B) for RTD CT (293/2.3 A)---7.5 VA (2) Neutral CT on LV Neutral for Protection (Burden -15 VA, Knee point voltage 300 V) (core 1-Class 5P 20:-CTR:-500/1 for SEF)

• TERMINAL CONNECTIONS : (suitable for cable connection ) 1. Terminal connections ( A/B/C ) HV Winding Line End : B LV Winding Line End : B and Voltage class of neutral bushing LV Winding Neutral End : B 2. Earthling Conductor Material : GS Size : 60 X 10

• MISCELLANEOUS: 1. Impulse Test. Full Wave Required or not Required} : Chopped Wave Required or not Required } 2. Heat Run Test Required or not Required } 3. Buchholz Relay Required or not Required : Required 4. Winding Temperature Indicator Required or not Required : Required 5. Oil Level Guage Type: Magnetic of Size : 150 mm Type: Prismatic : Required 6.Colour shade of final painting as per IS:5 : : Light Grey as per Shade 631 7.Bolted joint near base of Tank Required or not Required : Not Required 8. Skids Required or not Required : Required 9. Wheel Plain/Flanged : Plain Unidirectional/Bidirectional : Uni-Directional 10.Vacuum Withstand Capacity Main Tank with bushings,} Fittings &accessories } : Full Vacuum Radiators : Full Vacuum

• NGR of 3500 KVA transformer for 6.9 KV side --- Rated voltage :----------------------------------------- 6.9 KV Rated current :----------------------------------------400A Rated duty :---------------------------------------------10 Sec. Rated Resistance:---------------------------------------9.96 +/- 10% Temp.rise :----------------------------------------------375 degree c over 50 degree c Service :------------------------------------------------outdoor IP 43 as per IS-2147


Installed

NOTES

1. A. Bare terminals on bushings stem for connection to rigid bus-bar / overhead conductors. B. HV & LV side Cable box type with a disconnecting chamber for connecting to zPurchaser’s

cables. C. If impulse test has already been conducted on identical transformers, the test reports of the

same shall be enclosed with the bid.

• CABLE SIZE :

11 kV earthed grade 1 X 3 C X150 sq. mm for HV line end of transformer.

11 kV 3C X 300 sq.mm.cable XLPE For LV line end of transformer



Installed

SECTION –IV

BIDDING SCHEDULES (To be filled in and signed by the tender)

SCHEDULE - A

Schedule of Guaranteed Technical particulars for voltage

Transformers.

Technical particulars 1.0 Transformer application/Designation. : 2.0 Quantity required. Nos. : 1 3.0 Full load rating. KVA : 4.0 3 phase unit/ 1phase unit : 5.0 Auto wound/two winding transformer/ } : three winding transformer. } 6.0 Rated no-load voltage : 6.1 H.V. KV : 6.2 L.V. KV : 7.0 Cooling (ON/OB/FB/OFB/OW/OFN etc.) : 8.0 Rating if assigned corresponding to the various methods of cooling. ON : KVA : 9.0 Rating of windings : 9.1 H.V. : KVA : 9.2 L.V. : KVA : 10.0 Rated percentage impedance : 10.1 H.V. – L.V. % : 11.0 Rated frequency. Hz : 12.0 Indoor/Outdoor installation : 13.0 Winding Connections 13.1 H.V. : : 13.2 L.V. : : 13.3 Vector group : : 14.0 Tappings on winding : 14.1 On Load/Off Load : : 14.2 Total tapping range : % : 14.3 On HV/LV winding : : 15.0 Winding insulation and category as per IS 2026 of graded insulation (a) HV- Full / graded category : (b) LV- Full / graded category : 16.0 Impulse Voltage withstand 1.2 / 50 µs wave. (a) HV kVpeak : (b) LV kVpeak : 17.0 Power frequency withstand

Voltage (dry & wet) (a) HV kVrms :


Installed

(b) LV kVrms : 18 Guaranteed Max . Temp. Rise :

(a) Oil by Thermometer °C : (b) Winding by Resistance

For ON Cooling. °C : 19 Tank cover conventional /

Bell Shaped : 20 Bushings HV LV (a) Rated Voltage Class kV : (b) 1.2 / 50 µs wave impulse withstand kVp : . (c) One minute power frequency Withstand (dry and wet) kVrms : (d) Minimum clearance in air

(Phase to phase) mm : (Phase to earth) mm : (e) Total minimum creepage distance mm :

21 Load loss at rated current at 75°C Winding temperature (guaranteed Subject to + 10% tolerance as per I.S.) kW :

22 No load losses (core loss& Dielectric loss ) at 100% rated Voltage &frequency subject to + 10%tolerance as per I.S. kW :

23 Magnetization current at rated Voltage & frequency:

23.1 when excited from LV side % : 23.2 When excited from LV side at 110% rated voltage % : 23.3 When excited from HV side at 110% rated voltage. % : 24.0 Maximum flux density in : (a) At rated voltage Wb/m2 : (b) At 110% rated voltage Wb/m2 : 25.0 Current Density :

(a) HV Amp/cm2 : (b) LV Amp/cm2 : 26.0 Wheels (a) Plain / Flanged : (b) Unidirectional /bidirectional. : (c) Quantity. Nos : (d) Gauge (s) :

27.0 Vacuum withstand capability : (a) Main Tank mm of Hg : (b) Radiators & Accessories. " 28.0 Dial size of magnetic oil level Gauge. mm : 29.0 Weight : 29.1 Core & Windings kgs : 29.2 Oil kgs. : 29.3 Tank, Coolers & fittings. Kgs : 29.4 Total. Kgs : 29.5 Untanking weight. Kgs : 30.0 List of routine tests to be Carried out. : 31.0 List of other tests which will be

Carried out against extra price quoted else where. :

32.0 Drawing number of the general }

outline drawing enclosed with } : the bid showing the transformer } with all its fittings and accessories }


Installed

in plan, front and side elevations } and other details. } 33.0 Shipping section 33.1 Size of largest package :

( L X B X H ) Length. mm. : Breadth mm : Height mm :

33.2 Weight of largest package: Kgs : 33.3 NGR of 3500 KVA transformer for 6.9 KV side ---

Rated voltage :----------------------------------------- Rated current :---------------------------------------- Rated duty :--------------------------------------------- Rated Resistance:--------------------------------------- Temp.rise :---------------------------------------------- Service :------------------------------------------------ IP 43 as per IS-2147

REMARKS (if any) :-



Installed

SECTION –IV

BIDDING SCHEDULES (To be filled in and signed by the tender)

SCHEDULE - B

DEVIATIONS FROM TECHNICAL SPECIFICATION

All the deviations from this specification shall be set out by the bidder, clause by clause, in this schedule. Unless specifically mentioned in this schedule, the bidder shall be deemed to confirm to the specification.

Reference Section and

page

Description of Exceptions / Deviations

Reason for Exception / Deviation



Installed

SECTION –IV BIDDING SCHEDULES

(To be filled in and signed by the tender)

SCHEDULE - C

PERFORMANCE AND EXPERIENCE DETAIL

Bidder shall furnish here a list of similar orders executed/under execution by him and name of persons to whom the reference may be made by the Purchaser in case he considers such reference necessary.


Sl. No.

Name of the Purchaser /

Owner with full address

Location of the Plant / Equipment

Date of Commis

sion ing

Performance Certificate submitted (Yes/No)

Details of Equipment supplied & installed

Person to whom

reference be made


Installed

SECTION - V

INFORMATION TO BE FURNISHED BYTHE VENDOR AFTER THE AWARD OF CONTRACT.

1.0 Positive sequence impedance at maximum voltage tap.

2.0 Positive sequence impedance at minimum voltage tap.

3.0 Zero sequence impedance at principal tap.

4.0 Efficiency at 75ºC winding temperature.

4.1 At 75% of full load



5.0 Maximum efficiency and load at which it occurs.

6.0 Regulation at full load at 75ºC Winding temperature at :

6.1 Unity power factor.

6.2 0.85 power factor lag.

7.0 Resistance per phase of :

HV winding : Ohms

MV winding : Ohms

LV winding : Ohms

8.0 Conductor area (sq.cm.)

HV winding

MV winding

LV winding

9.0 Type of windings

HV

MV

LV

10.0 Insulating materials for interterm insulation :

HV winding

MV winding

LV winding

11.0 Insulating materials for inter winding insulation :

HV-MV

MV-LV

12.0 Insulating materials between :

12.1 LV winding and core

12.2 Laminations of the core

13.0 Shipping details :

13.1 Size of the largest package (mm) (Length x width x height)

13.2 Weight of the largest package (Tones)

13.3 Total gross weight to be handled (Tones)

13.4 Total gross volume to be handled (cu.metres)

14.0 Make, type and size of all valves

15.0 Make, type, dial size, number of contacts (if provided) and contact ratings (current and voltage ratings) for the following.

15.1 Magnetic oil level gauge.

15.2 Dial type thermometer

15.3 Winding temperature indicator (local and remote)

16.0 Gas and oil actuated relay / sudden pressure relay.

Make

Type

Number of contacts

Contacts

a) Number

b) Voltage rating

c) Current rating.

17.0 Control switches :

Make

Type


Installed

Number of contacts (The VENDOR shall furnish contact development diagrams).

Contact rating.

18.0 Cubicle heaters

18.1 Rating (KW)

18.2 Number provided in cooler control cabinet.

19.0 Cubicle illumination lamps.

19.1 Rating of each (W)

19.2 Total numbers.

20.0 Conservator

20.1 Total volume of conservator (liters)

20.2 Volume of conservator between the highest and lowest levels of oil (liters)

21.0 Calculated time constants.

21.1 Natural cooling

22.0 Thermal withstand capability under full short circuit conditions, in terms of number of times of occurrence of short circuit and corresponding anticipated percentage reduction in transformer life. Relevant calculations shall be submitted.

23.0 DRAWINGS

The following drawings shall be submitted for the Purchaser’s approval :

23.1 General outline drawing as submitted at the bidding stage but with binding dimensions and weights within 2 months of award of contract.

23.2 General outline drawings showing plan, front elevation, and side elevation, with all fittings and accessories, locating dimensions of cable entries, earthing terminals, foundation / floor fixing details, jacking pads and weights of the following within 4 months of award of contract.

23.2.1 Cable boxes.

23.2.2 Disconnecting chambers.

23.3 Bushings

Plan, elevation, terminal details, mounting details, make and type of number, current and voltage rating, creepage distances and principal characteristics

23.4 Rating and diagram plates.

23.5 Marshalling box terminal connections wiring diagram.

DRAWING AND INSTRUCTION MANUALS 1.0 DRAWINGS

1.1 Within three weeks from the date of receipt of the order, the VENDOR / CONTRACTOR shall submit four copies of the list of all drawings he proposes to submit for approval identifying each by a serial number and descriptive title and giving the expected data of submission. This list shall be revised and extended, as necessary, during the progress of work.

1.2 After the award of contract, the VENDOR / CONTRACTOR shall submit (as per the Distribution Schedule enclosed with the Specification) copies of design calculations, material specifications and detailed drawings as called for in the equipment specification for the PURCHASER / ENGINEER’S review. The VENDOR / CONTRACTOR must satisfy the PURCHASER / ENGINEER as to the validity of his design with reference to the requirements of Statutory Code Authorities.

1.3 Drawing submitted for approval shall be signed by responsible representatives of the VENDOR / CONTRACTOR and shall be to any one of the following sizes in accordance with Indian Standards : Ao, A1, A2, A3 or A4.

1.4 All drawings shall show the following particulars in the lower right hand corner in addition to the VENDOR / Contractor’s name :

1.4.1 Name of the PURCHASER.

1.4.2 Project Title.

1.4.3 Purchase Order No.

1.4.4 Title of Drawing.

1.4.5 Scale.

1.4.6 Date of Drawing.

1.4.7 Drawing Number

1.4.8 Space for the Engineer's drawing number.

1.5 In addition to the information provided on drawings, each drawing shall carry a revision number, date of revision and brief details of revisions carried out. Whenever any revision is carried out, correspondingly revision number must be updated.

1.6 Al dimensions on drawings shall be in metric units, unless otherwise specified.

1.7 The PURCHASER / ENGINEER will return to the VENDOR / CONTRACTOR (a) one print stamped ‘Approved’ or (b) one print stamped ‘Approved with comments as noted’, or (c) one print marked with comments. In the case of (a) no further submission of the drawings is required. In the case of (b) the VENDOR / CONTRACTOR shall correct his original drawing to furnish the corrected drawings to the


Installed

PURCHASER / ENGINEER for the purpose of records. In the case of (c) the VENDOR / CONTRACTOR shall correct his original drawing to conform with comments and corrections of the PURCHASER / ENGINEER and resubmit the drawings to the PURCHASER / ENGINEER within two (2) weeks after receipt of the marked – up print for approval.

1.8 Drawing submitted by the VENDOR / CONTRACTOR for approval will be checked / reviewed by the PURCHASER / ENGINEER and comments, if any, on the same will be conveyed to the VFENDOR / CONTRACTOR to incorporate correctly all the comments conveyed by the PURCHASER / ENGINEER on the VENDOR / Contractor’s drawings. The drawings which are approved with comments are to be resubmitted to the PURCHASER / ENGINEER for purpose of records. Such drawings will not be checked / reviewed by the PURCHASER / ENGINEER to verify whether all the comments have been incorporated by the VENDOR / CONTACTOR. If the VENDOR / CONTRACTOR is unable to incorporate certain comments in his drawings he shall clearly state in his forwarding letter such non-compliance along with valid reasons.

1.9 Any work performed or material ordered by the VENDOR / CONTRACTOR prior to receipt of drawings stamped ‘Approved with comments as noted’ by the PURCHASER / ENGINEER shall be at the risk of the VENDOR / CONTRACTOR. After print of any drawing has been returned ‘Approved’, the VENDOR / CONTRACTOR may release all parts covered by the drawing, for production.

1.10 Reproducible, where called for in the distribution schedule, Section-F shall be submitted after the approval of drawings. These should be quality not less than a Kilburn reproducible tracing film or equivalent capable of producing clear and legible prints. “Sepia’ or similar process reproducible shall not be accepted.

1.11 Upon completion of the installation, the VENDOR / CONTRACTOR shall furnish a complete set of drawings on Kilburn reproducible tracing film or equivalent, if called for in the distribution schedule, Section-f or other parts of the specification n which the VENDOR / CONTRACTOR shall make in a neat and accurate manner, a complete record of all changes and revisions to the original design, as installed in the completed work. These drawings shall be submitted to the PURCHASER / ENGINEER for records, these become the property of the PURCHASER.

1.12 Drawings prepared by the VENDOR / CONTRACTOR and approved by the PURCHASER ./ ENGINEER shall be considered as a part of the specification. However, examination and approval of the drawings by the PURCHASER / ENGINEER shall not relieve the VENDOR / CONTRACTOR of his responsibility for engineering, design, workmanship and materials, under the Contract.

1.13 If, at any time before the completion of the work, changes are made necessitating revision of approved drawings, the VENDOR / CONTRACTOR shall make such revisions and proceed in the same routine as for the original approval.

2.0 INSTRUCTION MANUALS

2.1 Instruction Manual shall be written in English Language only.

2.2 The VENDOR / CONTRACTOR shall furnish required number of bound copies (as indicated in the distribution schedule) of Instruction Manuals for installation, operation and maintenance of all the equipment furnished by him.

2.3 Full and comprehensive Instruction Manuals shall be provided. They shall give a step by step procedure for all operations likely to be carried out during the life at the Plant / Equipment including erection, commissioning, testing, operation, maintenance, dismantling and repair. Each manual shall also include a complete set of approved drawings together with performance / rating curves of equipment and test certificates wherever applicable.

2.4 A separate section of the manuals shall be devoted to each size / type of equipment and shall contain a detailed description of construction and operation, together with all relevant pamphlets, drawings and a list of parts with procedure for ordering spares. Maintenance instructions shall include charts showing lubrication, checking, testing and replacement procedures to be carried out daily, weekly, monthly and at longer intervals to ensure trouble-free operation. Where applicable, fault location charts shall be included to facilitate finding the cause of mal-operation or breakdown. A collection of the MANUFACTURER’S standard leaflets will not be accepted, to mean compliance of this clause. The manual shall be specifically compiled for the concerned project.

2.5 The VENDOR / CONTRACTOR shall submit as called for in distribution schedule, Section-f preliminary copies of Instruction Manuals for review and approval before issue of final copies.

2.6 Three (3) copies of the final manual shall be mailed at the time of dispatch of equipment and remaining shall accompany the equipment.
