Technical Specification of GECOL. Packaged Transformers

Transcription

1 GES Technical Specification of GECOL Packaged Transformers (Revision history) Issued on: Jan. 01, 2007 General Electricity Company of Libya

2 Contents 1 SCOPE AND SERVICE CONDITIONS SCOPE SERVICE CONDITIONS Normal service conditions Unusual service conditions NORMATIVE REFERENCES DEFINITIONS NON-EXTENSIBLE RMU EXTENSIBLE RMU STRIKER OIL-IMMERSED TYPE TRANSFORMER NO-LOAD LOSS NO-LOAD CURRENT LOAD LOSS TEMPERATURE RISE LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR ASSEMBLY BUSBAR MAIN BUSBAR DISTRIBUTION BUSBAR ENCLOSED SWITCHBOARD INCOMING UNIT OUTGOING UNIT KINDS AND RATINGS KINDS RATING Rated voltage Rated frequency Rated insulation level Rated duration of short-circuit Rated current /38

3 4.2.6 Temperature rise Vector group and winding connection of transformer REQUIREMENTS GENERAL REQUIREMENTS Compartments Components Enclosure REQUIREMENTS OF HV COMPARTMENT General requirements Ring switch Operation device(s) Cable testing facility Fluid pressure gauge Requirements for gases in ring switch Circuit breaker for T-off Terminations and cable boxes Bus-bars Manual operation device Stored energy closing Earthing of ring switches Interlock Mimic diagram Other requirements REQUIREMENTS OF TRANSFORMER COMPARTMENT General requirements Type Off circuit tapping Cooling Core Windings Earthing terminal Fittings Tank Tank finish Gaskets Short circuit impedance /38

4 Temperature rise No load loss and load loss No-load current Voltage drop Efficiency Bushing Sound level Insulation oil Protection relay for the transformer Other requirements REQUIREMENTS OF LV COMPARTMENT General requirements Incoming MCCB, outgoing MCCBs and auxiliary MCCB Busbar(s) LV CTs Current meter Digital watthour meter Terminals of MCCB for outgoing cables Insulated conductors in LV compartment Earthing terminal Single diagram Resistance to abnormal heat and fire Protection against electric shock Short-circuit protection and short-circuit withstand strength Switching devices and components installed in the switchboard Other requirements TESTS TYPE TESTS Type tests of ring switch Type tests of CB Type tests of transformer Type tests of LV compartment ROUTINE TESTS Routine tests for whole packaged transformer Routine tests of ring switch Routine tests of CB /38

5 6.2.4 Routine tests of transformer Routine tests of LV compartment RATING PLATES RATING PLATE FOR PACKAGED TRANSFORMER RATING PLATE FOR HV COMPARTMENT RATING PLATE FOR TRANSFORMER COMPARTMENT RATING PLATE FOR LV COMPARTMENT MARKING ENCLOSURE OF PACKAGED TRANSFORMER HV COMPARTMENT Position-indicating device Spring-charge indicator (only for spring operation type) TRANSFORMER COMPARTMENT PACKING AND DELIVERY SPARE PARTS DOCUMENT AND CERTIFICATE INFORMATION TO BE PROVIDED WITH THE BID DOCUMENTS TO BE APPROVED BY GECOL DOCUMENTATION WARRANTY /38

6 GES (Technical Specification of GECOL) Packaged Transformers 1 Scope and service conditions 1.1 Scope This specification covers the 11/0.4kV packaged transformers for outdoor use which consist of 11kV switch system, 11/0.4kV distribution transformer and 0.4kV switch system on underground GECOL distribution network. 1.2 Service conditions Normal service conditions The packaged transformers shall be installed at outdoors in Libya and shall be suitable for continuous operation at the below site conditions. (a) Maximum altitude: 1,000m (ASL) (b) Maximum ambient air temperature: +50 C (c) Minimum ambient air temperature: -10 C (d) Monthly average temperature of the hottest month: 40 C (e) Yearly average temperature: 30 C Unusual service conditions Conditions other than those listed in for transformers are considered to be unusual. The manufacturer should discuss with GECOL for the unusual service conditions. 2 Normative references The packaged transformers shall confirm to the latest edition of following international standards: (a) IEC 60050(441): IEV Part 441: Switchgear, controlgear, fuses (b) IEC 60076: Power transformers (c) IEC 60137: Insulated bushings for alternating voltages above 1,000V (d) IEC 60228: Conductors of insulated cables (e) IEC : High-voltage fuses - Part 1: Current-limiting fuses (f) IEC 60296: Specification for unused mineral insulating oil for transformers and switchgear 6/38

7 (g) IEC : Low-voltage fuses Part 1: General requirements (h) IEC : Low-voltage fuses Part 2: Supplementary requirements for fuses for use by authorized persons (i) IEC 60354: Loading guide for oil-immersed power transformers (j) IEC : Low-voltage switchgear and controlgear assemblies Part 1: Typetested and partially type-tested assemblies (k) IEC 60427: Synthetic testing of high-voltage alternating current circuit breakers (l) IEC 60529: Degrees of protection provided by enclosures (IP code) (m) IEC : Low-voltage switchgear and controlgear Part 1: General rules (n) IEC : Low-voltage switchgear and controlgear Part 1: Circuit breakers (o) IEC 61634: High-voltage switchgear and controlgear - Use and handling of sulphur hexafluoride in high-voltage switchgear and controlgear (p) GES : Unused mineral insulating oil for transformers (q) GES 22210: 11/0.4kV Oil Immersed Ground Mounted Three Phase Conservator Type Distribution Transformers (r) GES 22214: 11/0.4kV Oil Immersed Ground Mounted Three Phase Sealed Type Distribution Transformers (s) GES 34130: Ring Main Unit (t) GES 34710: Low voltage switchgear and controlgear assembly for distribution stations 3 Definitions 3.1 Non-extensible RMU The RMU equipped with 2 ring switches and 1 fuse-switch (or CB) 3.2 Extensible RMU The RMU composed individually and connected to each other upon users requests 3.3 Striker The mechanical device forming part of a fuse-link which, when the fuse operates, releases the energy required to cause operation of other apparatus or indicators or to provide interlocking 3.4 Oil-immersed type transformer A transformer of which the magnetic circuit and windings are immersed in oil 3.5 No-load loss The active power absorbed when rated voltage (tapping voltage) at rated frequency is 7/38

8 applied to the terminals of one of the windings, the other winding or windings being opencircuited 3.6 No-load current The r.m.s. value of the current flowing through a line terminal of a winding when rated voltage (tapping voltage) is applied at rated frequency, the other winding or windings being open circuited 3.7 Load loss The absorbed active power at rated frequency and reference temperature associated with a pair of windings when rated current (tapping current) is flowing through the line terminals of one of the windings, and the terminals of the other winding are short circuited. 3.8 Temperature rise The difference between the temperature of the part under consideration and the temperature of the external cooling medium 3.9 Low-voltage switchgear and controlgear assembly The combination of one or more low-voltage switching devices together with associated control, measuring, signaling, protective, regulating equipment, etc., completely assembled under the responsibility of the manufacturer with all the internal electrical and mechanical interconnections and structural parts 3.10 Busbar The low-impedance conductor to which several electric circuits can be separately connected 3.11 Main busbar The busbar to which one or several distribution busbars and/or incoming and outgoing units can be connected 3.12 Distribution busbar The busbar within one section which is connected to a main busbar and from which outgoing units are supplied 3.13 Enclosed switchboard The switchboard which is enclosed on all sides with the possible exception of its mounting surface in such a manner as to provide a degree of protection 3.14 Incoming unit The functional unit through which electrical energy is normally fed into the assembly 8/38

9 3.15 Outgoing unit The functional unit through which electrical energy is normally supplied to one or more outgoing circuits 4 Kinds and ratings 4.1 Kinds Rated power of packaged transformer shall be determined according to the Table 1 of this specification. Table 1 Kinds of packaged transformers Specification No. Rated Power (kva) Rating Rated voltage Rated voltage shall comply with the Table 2 of this specification. Compartment HV switch compartment Table 2 - Rated voltage Transformer Compartment HV LV LV switch compartment Nominal voltage (kv) System highest voltage (kv) Rated frequency Rated frequency shall be 50Hz Rated insulation level Rated withstand voltages shall comply with the Table 3 of this specification. Table 3 - Rated insulation level Transformer Compartment HV LV HV LV Power-frequency withstand voltage (kv rms ) /38

10 Lightning impulse withstand voltage (kv peak ) Rated duration of short-circuit Rated duration of short-circuit shall comply with the Table 4 of this specification. Table 4 Short circuit duration Compartment HV Transformer LV Short circuit duration (Sec.) Rated current Rated current shall comply with the Table 5 of this specification. Table 5 - Rated current Compartment Rated current (A) HV Ring switch 630 CB 400 Transformer 500 kva 750 kva 1000 kva HV 26 LV 722 HV 39 LV 1,083 HV 52 LV 1,443 Incoming MCCB 1, LV Outgoing MCCB 400 MCCB for auxiliary power 2 pole 40A Temperature rise Temperature rise shall comply with the Table 6 of this specification. Table 6 Temperature rise Compartment HV Oil Transformer Winding LV 10/38

11 Temperature rise Table 3 of IEC C 55 C Table 2 of IEC Vector group and winding connection of transformer Vector group and winding connection shall comply with Table 7 of this specification. Table 7 Vector group and winding connection of transformer Rated voltage ratio (kv/kv) 11/0.4 Vector group (kv) Connection of HV windings Connection of LV windings Dyn11 (3-phase 3-wire) Y (3-phase 4-wire) (Neutral point shall be solidly earthed) 5 Requirements 5.1 General requirements Compartments The packaged transformer shall consist of HV compartment, transformer compartment and LV compartment. All compartments shall be contained in a metal enclosure suitable for outdoor installation Components HV compartment shall consist of 2 nos. of ring switches, a CB for transformer, 3 nos. of earthing switches, 3 nos. of disconnection switches, 11kV cable entering structure and other necessary equipment. Transformer compartment shall consist of a three phase oil immersed distribution transformer, connection cables and other necessary equipment. LV compartment shall consist of bus bar, MCCBs, digital meter, 0.4kV cable outgoing structure and other necessary equipment Enclosure A sheet steel enclosure shall contain 3 compartments. The enclosure shall be treated and painted to withstand salt fog, humidity and dust contamination. All panels shall be cleaned, primed then painted with a finish coat as required for outdoor installation. Color of the final paint coat shall be light gray. The enclosure shall be designed for outdoor use to provide adequate ventilation for transformer. 3 hinged doors shall be provided at each compartment and operation of HV 11/38

12 and LV panels shall be possible in the front of each panel. The doors shall not obstruct cable jointing work, switch operation work, transformer tapping work and check / repair works when the doors are opened. Locking device of each door shall be provided. Protection degree of enclosure shall be IP44 or better in accordance with IEC All accessories for installation, operation and maintenance, such as mounting frames, operating rods, nuts & bolts, and so on, shall be provided with the packaged transformer. 5.2 Requirements of HV compartment General requirements (a) HV panel shall be equipped with two ring switches for feeders and one CB for the T- off circuit linked to a distribution transformer. (b) Ring switch shall be SF 6 gas insulated type or equivalent. (c) T-off CB shall be vacuum interrupt type. (d) The operation devices shall be three-position switches and be arranged in order closed - open - earthed. If approved by GECOL, DS and ES can be applicable respectively. (e) The operation shall be possible in the front of the HV panel Ring switch (a) The ring switch shall be able to break and make the rated current of 630A. (b) The ring switch shall be able to withstand 16kA of short time current and 40kA peak current Operation device(s) The operation device(s) to close, open and earth the main contact shall be provided and meet the followings. (a) The operation shall be possible in the front of the HV panel. (b) The operation device(s) shall be three-position switch(es), and be arranged in order closed - open - earthed Cable testing facility The ring switch shall have test bushings or test probe insertion facility for high voltage and current injection tests for the cables terminated at the ring switches. Disconnection of cables for testing purpose is not acceptable Fluid pressure gauge If SF6-gas insulated switch, the gas pressure gauge shall be equipped with the ring switch, and operational pressure range shall be indicated on the gas pressure gauge. 12/38

13 5.2.6 Requirements for gases in ring switch (a) For ring switch with gas, the supplier shall specify the type and the required quantity, quality and density of the gas to be used in switches and provide GECOL with necessary instructions for renewing the gas and maintaining its required quantity and quality. (b) For SF 6 -filled switches, new sulphur hexafluoride shall comply with related provisions of IEC Circuit breaker for T-off (a) The rating of the CB shall be in compliance with the sub-clauses listed below. - Rated voltage: 12 kv - Rated current: 400 A - Rated short-circuit breaking current: not less than 12.5 ka (b) The CB shall be equipped with a bushing CT per each phase for protection purpose, and the accuracy class of the CT shall be equivalent to or better than 10P class. The CT shall conform to the GES titled Current Transformer. (c) The CB shall be equipped with the devices to release the signals for tripping the CB when the current of each phase through the CB exceeds the value specified, and also equipped with the device to release the signal for tripping the CB when the zero sequence current through the CB exceeds the value specified. - The relay(s) on the CB are acceptable. - The tripping coils with fuses are acceptable. (Refer to the Appendix B of this specification) - Others equivalent to or better than the methods listed above are acceptable, if approved by GECOL. (d) Unless otherwise mentioned above, the GES titled High Voltage Alternating-current Circuit-breakers shall be taken into consideration Terminations and cable boxes (a) The termination for the ring switch shall be inside the cable box and suitable for threecore XLPE insulated aluminum or copper cable with its size of up to 3c x 240 mm 2. (b) The termination for the T-off switch shall be inside the cable box and suitable for three-core XLPE insulated aluminum or copper cable with its size of up to 3c x 240 mm 2. (c) Each cable box shall be structured to be able to be equipped with a gland. (d) All devices and equipment for cable terminations shall be provided by the supplier. 13/38

14 5.2.9 Bus-bars The rated current of the bus-bar shall not be less than that of the ring switches Manual operation device The manual operating mechanism shall be provided. The operating handle have antireflex and shall be stored at the front of panel. The operating handle shall be used commonly for all operations of both ring and CB. Operating handle inserts shall have appropriate marking to avoid wrong insertion of handle during switch operations Stored energy closing (a) A ring switch arranged for stored energy closing shall be able to open immediately following the closing operation with the rated short-circuit making current. (b) The main contacts shall only move under the action of the drive mechanism and in the designed manner, and not in the case of reapplication of the energy supply after a loss of energy Earthing of ring switches (a) The frame of each device shall be provided with a reliable earthing terminal having a clamping screw or bolt for connection to an earthing conductor suitable for fault conditions. (b) The diameter of the clamping screw or bolt shall be at least 12 mm. (c) The connecting point shall be marked with the "protective earth" symbol, and the size of the symbol shall clearly visible in front of HV panel Interlock The interlock shall be provided to make sure of followings as minimum. (a) The operation of the ring switch shall not be able to move directly from the close position to the earthed position nor from the earthed position to the close position. (b) Closing operation of the ring switch with the test plug inserted and/or switch cover open shall be blocked. (c) Opening of cable boxes without the associated ring switch in the Earth position shall be blocked Mimic diagram The mimic diagram shall be provided on the front side of the HV panel with the necessary graphical symbols and indicators. The mimic diagram shall contain at least the following devices. (a) Bus-bar(s) (b) Switch position indicators (including the earthed switch) 14/38

15 (c) Switch operating devices (including the earthed switch) (d) Transformer symbols Other requirements Other requirements shall comply with GES Requirements of transformer compartment General requirements (a) The transformer shall be connected with HV compartment and LV compartment by means of suitable size of cables. (b) Transformer compartment of shall be taken into consideration of ventilation conditions for temperature rise of transformer. (c) Transformer shall be fixed with the base of enclosure and shall have enough clearance with wall and ceiling Type The transformers shall be oil immersed, sealed type or conservator type Off circuit tapping The HV winding of the transformers shall have 5 tapping positions they are principal tapping and ± 2.5% 2 tapping positions operated by an off-circuit tapping switch clearly marked position indicator. Tapping position shall be visible at the safe distance. Tap changer shall have locking device. Switching position of No. 1 shall correspond to maximum plus tapping Cooling Cooling system of the transformers shall be natural circulation of oil and air (ONAN) Core The core shall be constructed of the best quality low loss, cold-rolled grain oriented steel laminations confirming with the latest edition of IEC The flux density in any part of the core shall not exceed 1.72 Tesla at nominal voltage and frequency. Thickness of a lamination shall not exceed 0.3mm (M5) Windings The windings shall be made of best soft drawn copper having high conductivity and complying with the requirements of the latest edition of IEC The windings shall be designed to meet the three fundamental requirements: mechanical, thermal and electrical. The windings shall be capable of sustaining short circuit forces on the transformer as 15/38

16 required in Table 4 of this specification Earthing terminal Earthing terminal shall be parallel groove clamp type or I bolt type. The terminal shall be able to connect the earthing wire of which cross sectional area between 25mm 2 and 70mm 2. It shall be located at the bottom on the HV side Fittings The transformer shall be equipped with following accessories as minimum. (a) Oil level gauge (b) Oil temperature indicator (c) Over pressure relief valve (if sealed type) (d) Lifting lugs for lifting of whole transformer (e) Oil filling hole and cap (f) Valve at the bottom of the tank for oil filtering and drain (g) Oil sampling cock Tank Tank shall be fabricated of excellent quality mild steel. The tank shall be designed so that the completed transformer can be lifted and transported without deformation or oil leakage. The tank shall withstand pressures developed during normal and abnormal operation of the transformer without permanent deformation. The tank shall be electrically welded and tested for leaks Tank finish The painting process of steel parts shall ensure that no corrosion takes place. Prior to the painting of the tank, the cover and oil conservator shall be sand-blasted or shot-blasted for removal of mill and welding scale. The painting shall be made with a single coat of onepack epoxy paint. The finishing paint shall be made with two or three coats. The primer coat shall contain rust inhibitor, both oil and heat resistant. Secondary coats shall contain resistant components of salt spray, chemicals and humidity. Minimum thickness of coats shall not less than average 60µm and shall not less than 80% at any point. The out side color of the tank shall be painted in light grey Gaskets All the gaskets used for sealing the tanks and connected external parts shall be made of NBR (Nitrile (Acrylonitrile) Butadiene Rubber) or better that totally prevents the leakage of oil and ingress of humidity and air to the oil and windings under all operating conditions. The minimum thickness shall be 6mm. The gaskets shall not have any joint and shall withstand insulation oil. It shall not have variation of characteristics caused by temperature 16/38

17 variation Short circuit impedance The minimum short circuit impedance shall comply with Table 8 of this specification. Rated Power Table 8 Minimum short circuit impedance Minimum short circuit impedance 500 kva 4 % 750 kva 5 % 1000 kva 5 % The guaranteed short circuit impedance shall be stated by the supplier. The tolerance shall be ±10.0% of the declared value at principal tapping and ±15.0% of the declared value at other tappings Temperature rise The transformers shall be capable of carrying their full normal rated current continuously under the worst temperature conditions encountered in Libya. Temperature rise of top oil shall not exceed 50 as measured by thermometer and temperature rise of winding shall not exceed 55 as measured by resistance No load loss and load loss Load loss and no load loss shall be stated by the supplier and shall not exceed the values of Table 9 of this specification. Tolerance shall not exceed +15% of no load loss, +15% of load loss and +10% of total loss. Table 9 - No-load loss and load loss limit Rated Power No Load Loss (W) Load Loss (W) No-load current 500 kva 1,070 7, kva 1,460 9, kva 1,815 12,200 No-load current shall not exceed the value of Table 10 of this specification. Tolerance shall not exceed +30% of the declared value. Rated Power Table 10-No load current Maximum No Load Current 500 kva 2.0 % 750 kva 1.5 % 17/38

18 Voltage drop 1000 kva 1.5 % The maximum voltage drop shall not exceed the values in Table 11 of this specification. All values shall be measured at 1.0 power factor, 100% load and adjusted to Efficiency Rated Power Table 11 Voltage drop limit Maximum Voltage Drop 500 kva 1.5% 750 kva 1.4% 1000 kva 1.4% The minimum efficiency shall be equal or exceed the values in Table 12 of this specification. All values shall be measured at 1.0 power factor, 100% load and adjusted to Bushing Rated Power Table 12 Minimum efficiency Minimum Efficiency 500 kva 98.4% 750 kva 98.5% 1000 kva 98.6% The electrical characteristics of bushings shall meet the requirements of IEC and IEC Sound level All transformers with their accessories shall be designed and manufactured to reduce noise and vibration to acceptable level. The average surface sound level of transformers shall not exceed the following values. The transformer shall be subjected to sound level measurement as per IEC Rated Power Table 13 Sound level limit Maximum Sound Level 500 kva 56 db 750 kva 57 db 1000 kva 58 db 18/38

19 Insulation oil The transformer shall be supplied with being filled with mineral insulation oil. The characteristics of insulation oil shall meet the Table 2 of IEC and GES The oil shall not be contaminated by Poly Chlorinated Biphenyls (PCB) Protection relay for the transformer The transformer shall be equipped with a set of relays, and the relays shall meet the requirement below. (a) Percentage differential current relay (87T) with over-current function shall be provided. (b) The auxiliary equipment for the relays, such as CT and PT, shall be provided. (c) Unless otherwise mentioned above, GES titled Percentage Differential Current Relays shall be referred Other requirements Other requirements shall comply with GES and GES Requirements of LV compartment General requirements LV compartment shall be at the opposite side of HV compartment and shall have following components as minimum. (a) Incoming MCCB, outgoing MCCBs and auxiliary MCCB (b) Busbar(s) (c) LV CTs (d) Current meter (e) Electronic watthour meter Incoming MCCB, outgoing MCCBs and auxiliary MCCB Rating and number of incoming MCCB from transformer and outgoing MCCBs to LV feeders shall follow the Table 14 of this specification. The MCCB shall be 3 pole type. Rated power of transformer (kva) 500 Table 14 Rating and number of MCCB and CT ratio Incoming MCCB Outgoing MCCB Current ratio of CT Number Rating Number Rating 800A 3 400A 1,000/5A ,200A 4 400A 1,500/5A 1,000 1,600A 6 400A 2,000/5A 19/38

20 An auxiliary MCCB shall be single phase 2 pole type and current rating shall be 40A Busbar(s) Rated current of busbar shall not be less than 1,600A LV CTs LV compartment shall be equipped with 3 nos. of LV CTs for current measuring at primary side of incoming MCCB. The current ratio shall comply with Table 14 of this specification. Accuracy shall be ±1.0% Current meter 1 or 3 nos. of digital type or analog type current meter(s) shall be provided. Current range shall be 0~5A. If a current meter is provided, there shall be a phase selection switch shall be provided together Digital watthour meter The digital watthour meter shall be 3 phase 4 wire and equipped with following functions as minimum. Accuracy shall be ±1.0%. (a) Watthour (kwh) (b) Demand (c) Power factor Terminals of MCCB for outgoing cables (a) The terminals of MCCB for outgoing cables shall be suitable for connection of copper or aluminum conductors. The terminals shall be such that the outgoing cables may be connected by suitable means such as screws, connectors, etc. which ensures that the necessary contact pressure corresponding to the current rating and the short-circuit strength of the apparatus and the circuit is maintained. (b) The terminals shall be suitable for connection of 4 core LV copper or aluminium cable up to 240mm Insulated conductors in LV compartment (a) The connections of current-carrying parts shall not suffer undue alteration as a result of normal temperature rise, ageing of the insulating materials and vibrations occurring in normal operation. (b) The connections between current-carrying parts shall be established by means which ensure a sufficient and durable contact pressure. (c) Busbars shall be completely insulated except for connection parts to prevent an electric shock and a power failure by proper means, such as heat shrinkable insulation tubes, epoxy coating or etc. 20/38

21 5.4.9 Earthing terminal (a) The earthing terminal having a clamping screw or bolt for connection to an earthing conductor shall be suitable for fault conditions. And the diameter of the clamping screw or bolt of the earthing terminal shall be at least 12 mm. (b) The connecting point shall be marked with the "protective earth" symbol as below, and the size of the symbol shall be clearly visible in front of LV panel Single diagram The single diagram shall be provided on the front of the LV panel with the suitable graphical symbols Resistance to abnormal heat and fire The parts of insulating materials which might be exposed to thermal stresses due to electrical effects, and the deterioration of which might impair the safety of the switchboard, shall not be adversely affected by abnormal heat and by fire Protection against electric shock For protection against electric shock, the clause 7.4 of IEC shall be taken into consideration Short-circuit protection and short-circuit withstand strength The clause 7.5 of IEC shall be taken into consideration Switching devices and components installed in the switchboard The switching devices and components installed in the switchboard shall comply with the clause 7.6 of IEC Other requirements Other requirements shall comply with GES Tests Routine tests shall be repeated in the presence of GECOL representatives on 10% of the quantity offered for inspection, chosen at random, subject to a minimum of 2 Nos. of packaged transformer. 6.1 Type tests Type tests of ring switch (a) Dielectric tests: IEC clause 6.2 (b) Measurement of the resistance of the main circuit: IEC clause 6.4 (c) Temperature-rise tests: IEC clause /38

22 (d) Short-time withstand current and peak withstand current tests: IEC clause 6.6 (e) Verification of protection: IEC clause 6.7 (f) Tightness tests: IEC clause 6.8 (g) EMC tests: IEC clause 6.9 (h) Additional tests on auxiliary and control circuits: IEC clause 6.10 (i) Making & breaking test: IEC clause (j) Mechanical operation test: IEC clause (k) Pressure withstand test for gas-filled compartments: IEC clause (l) Weatherproofing test: IEC clause (j) Internal arcing test: IEC clause Type tests of CB (a) Dielectric tests: IEC clause 6.2 (b) Radio interference voltage tests: IEC clause 6.3 (c) Measurement of the resistance of the main circuit: IEC clause 6.4 (d) Temperature-rise tests: IEC clause 6.5 (e) Short-time withstand current and peak withstand current tests: IEC clause 6.6 (f) Tightness tests: IEC clause 6.8 (g) EMC tests: IEC clause 6.9 (h) Mechanical operation test at ambient temperature: IEC clause to (i) Short-circuit current making and breaking tests: IEC clause to (j) Capacitive current switching tests: - Cable-charging current breaking tests: IEC clause (k) Verification of the degree of protection: IEC clause Type tests of transformer (a) Temperature-rise test: IEC (b) Lightning impulse test: IEC (c) Chopped wave test: IEC (d) Measurement of zero-sequence impedance(s) on three-phase transformers: IEC , 10.7 (e) Short-circuit withstand test: IEC (f) Measurement of sound levels: IEC (g) Measurement of the harmonics of the no-load current: IEC , 10.6 (h) Leakage test for transformer tank and radiator Type tests of LV compartment (a) Temperature-rise test: IEC , (b) Dielectric properties test: IEC , /38

23 (c) Short-circuit withstand strength test: IEC , (d) Effectiveness of the protective circuit: IEC , (e) Clearances and creepage distances: IEC , (f) Mechanical operation test: IEC , (g) Verification of the degree of protection: IEC , (h) EMC tests: IEC , 7.10, Annex H 6.2 Routine tests Routine tests for whole packaged transformer (a) Visual inspection and component check (b) Structure of each compartment check Routine tests of ring switch (a) Dielectric test on the main circuit: 7.1 of IEC (b) Tests on auxiliary and control circuits: 7.2 of IEC (c) Measurement of the resistance of the main circuit: 7.3 of IEC (d) Tightness test: 7.4 of IEC (e) Design and visual checks: 7.5 of IEC (f) Mechanical operation tests: of IEC / of IEC (g) Pressure tests of gas-filled compartments (if applicable): of IEC (h) Tests after erection on site: of IEC (i) Measurement of fluid conditions after filling on site: of IEC Routine tests of CB (a) Dielectric test on the main circuit: 7.1 of IEC (b) Dielectric test on auxiliary and control circuits: 7.2 of IEC (c) Measurement of the resistance of the main circuit: 7.3 of IEC (d) Tightness test: 7.4 of IEC (e) Design and visual checks: 7.5 of IEC (f) Mechanical operating tests: 7.101of IEC Routine tests of transformer (a) Measurement of winding resistance: IEC , 10.2 (b) Measurement of voltage ratio and check of phase displacement: IEC , 10.3 (c) Measurement of short-circuit impedance and load loss: IEC , 10.4 (d) Measurement of no-load loss and current: IEC , 10.5 (e) Separate source voltage withstand test and induced overvoltage withstand test: IEC Routine tests of LV compartment (a) Inspection of the switchgear including inspection of wiring and, if necessary, electrical operation test: of IEC (b) Dielectric test: of IEC (c) Checking of protective measures and of the electrical continuity of the protective 23/38

24 circuit: of IEC Rating plates The packaged transformer and each compartment shall be provided with rating plates of weatherproof material, fitted in a visible position and clearly readable at safety distance when the packaged transformer is installed or cables are connected, showing the appropriate items indicated below but not limited. The characters shall be English roman letters and Arabic numeral characters. Symbols and text shall be indelibly molded, stamped or engraved in a plate material and they shall be at least 4.0 mm high. If not contrasting in colour, they shall be grooved at least 0.5 mm high. 7.1 Rating plate for packaged transformer (a) Product name: Packaged Transformer (b) Manufacturer's name (c) Manufacturer's serial number (d) Year and month of manufacture (e) Number of phases (f) Rated power in kva (g) Rated frequency in Hz (h) Total mass (i) Insulation level of HV and LV compartment (j) Dimension (k) Degree of protection (l) Normal operation conditions: Ambient temperature, altitude 7.2 Rating plate for HV compartment (a) Name of manufacturer (b) Year and month of manufacture (c) Rated voltage (d) Rated lightning impulse withstand voltage (e) Rated power frequency withstand voltage (f) Rated frequency (g) Rated normal current (h) Rated duration of short circuit (i) Rated short-time withstand current (for main and earthing circuits) (j) Rated peak withstand current (for main and earthing circuits) (k) Maximum & Minimum pressure of insulation 7.3 Rating plate for transformer compartment (a) Kind of transformer 24/38

25 (b) Applicable international standard (c) Manufacturer's name (d) Manufacturer's serial number (e) Year and month of manufacture (f) Number of phases (g) Rated power in kva (h) Rated frequency in Hz (i) Rated voltages and tapping range of HV(kV) and LV(V) (j) Rated currents of each tapping of HV and LV in A (k) Drawing of vector group (l) Short-circuit impedance, measured value in percentage (m) Type of cooling (n) Total mass (o) Mass of insulating oil (p) Insulation level of HV and LV (q) Temperature rises of top oil and windings (r) Insulating liquid (s) Normal operation conditions: Ambient temperature, altitude 7.4 Rating plate for LV compartment (a) Name of manufacturer (b) Year and month of manufacture (c) Rated operational voltage (d) Rated insulation voltage (e) Rated impulse withstand voltage (f) Rated current of busbar, incoming MCCB, outgoing MCCB, auxiliary MCCB (g) Rated frequency (h) Short-circuit withstand strength 8 Marking 8.1 Enclosure of packaged transformer (a) Warning mark High Voltage, Danger at 4 sides of enclosure. It shall be clearly visible at 5m distance. 8.2 HV compartment Position-indicating device The position-indicating device for the contact position of the main circuit shall be possible to easily check the state of the position-indicating device when operating locally. (a) Letter type and colors of the position-indicating device - The colors of the position-indicating device shall comply with the Table 15 of this 25/38

26 specification. Table 15 - Colors of the position-indicating device Position Symbol or letter Color Background Open Closed Earthed The color Contrasting with the background * Green Red Yellow * The color of green, red and yellow shall be excluded. - The letter font of the position-indicating device shall be Roman font, the size of the position-indicating device shall be at least 30 mm high. (b) Symbols and letters of the position-indicating device - The Symbols and letters of the position-indicating device shall comply with the Table 16 of this specification. Table 16 - Symbols of the position-indicating device Position Symbol Letter Open OFF * / OPEN Closed ON * / CLOSE Earthed EARTH * * : The preferred means are marked *. - Alternatively, in the case of a multi-function device, the positions may be marked with graphical symbols for diagrams of IEC Spring-charge indicator (only for spring operation type) The spring-charge indicator shall be possible to easily check the state of the charging device when operating locally. (a) Letter type and colors of the spring-charge indicator - The colors of the spring charge indicator shall comply with the Table 17 of this specification. Table 17 - colors of the spring charge indicator 26/38

27 Position Symbol or letter Color Background Charged The color Contrasting Yellow Discharged with the background * White * The color of green, red and yellow shall be excluded. - The letter font of the spring charge indicator shall be Roman font, the size of the position-indicating device shall be at least 30 mm high. (b) Symbols and letters of the spring charge indicator The symbols and letters of the spring charge indicator shall comply with the Table 18 of this specification. Table 18 - Symbols of the position-indicating device Position Symbol Letter Charged Discharged Specified by supplier CHARGE DISCHARGE 8.3 Transformer compartment (a) Rated power: Rated power and its unit shall be of salient character on middle position of tank wall on HV side. The salient part shall be painted with red color indelible paint. (b) Terminal symbol: HV terminal symbol shall be 1U, 1V and 1W from left side. LV terminal symbol shall be 2N, 2U, 2V and 2W from right side and indelibly marked in front of terminal bushings. (c) Earthing terminal marking shall be marked adjacent to earthing terminal. 9 Packing and Delivery The supplier shall provide packing of the packaged transformers as is required to prevent their damage or deterioration during transit to their final destination and long period of storage. The packing shall be sufficient to withstand, without limitation, rough handling during transit and exposure to extreme temperatures, salt and precipitation during transit and open storage. (a) All packaged transformers and its components shall be shipped from the factory to the specified site. (b) The enclosure shall be wrapped up in proper thickness of vinyl sheet to prevent 27/38

28 ingress of humidity. The enough amount of dehumidifying agent shall be inside. (c) Packing case size and weights shall take into consideration, where appropriate, the remoteness of the transformer's final destination and the absence of heavy handling facilities at all points in transit. (d) The parts of a packaged transformer shall be packaged by one set even though the numbers of transformers to be supplied are plural. (e) Each shipment shall include a detailed packing list identifying all items by part number, including hardware. (f) All material shall be carefully loaded for protection during shipment. (g) Small parts and fasteners shall be carefully boxed, crated, bagged or otherwise containerized and protected for shipment. (h) All materials shall be arranged to allow safe unloading at the site. (i) There shall be handling instruction to minimize damage. The outer packing must be clearly marked on at least four (4) sides as follows; (a) Name of the procuring department (b) Name of the supplier (c) Contract description (d) Final destination (e) Gross weight (f) Any special lifting instructions (g) Any special handling instructions (h) Any relevant pollution or environment classifications 10 Spare parts A list of recommended spare parts (along with the detailed prices) for five years trouble free operation shall be furnished with the offer. 11 Document and certificate The unit and all associated materials quoted by the supplier shall be approved by GECOL. The quantity of documents and certificates submitted shall be not less than three copies. The unit shall conform to the latest edition of IEC including Clause 2 of this specification or any other equivalent international standards. The design and construction of the unit shall be subjected to the approval of GECOL Information to be provided with the BID Technical descriptions, data sheets, catalogues and other information shall be submitted 28/38

29 with the BID and those which are submitted shall be sufficient to enable GECOL to evaluate thoroughly the proposal as to its compliance with the requirements of this specification. The minimum requirement is as follows: (a) Detailed summary of difference with this specification (b) Technical Data Sheet duly filled in and signed (Annex A) (c) Material safety data certificates of all chemical materials used for manufacturing such as insulating fluid, painting, gasket and gas, etc. (d) Detailed drawing of all components in A3 or A4 size (e) Detailed handling, installation and maintenance manual & schedule for good operation (f) Diagram of connections (g) Brochures and catalogues containing outline dimensions, main electrical and mechanical data, etc. (h) Applicable design specification and standards in English language (i) Test certificates approved by international institute (j) Quality control system and relevant certificate 11.2 Documents to be approved by GECOL The supplier shall furnish all relevant technical information, drawings etc. to GECOL for approval prior to the start of manufacture. Offers without Technical Data Sheet completely filled in will be rejected. (a) Vendor(s) details/ Reference list (b) Technical Data Sheet (c) Tests schedule and procedures (d) Transportation schedule and storage conditions (e) Drawings of materials (All drawings shall be in A3 or A4 size with title block approved by GECOL) 11.3 Documentation All documents supplied under this specification shall be documented to the extent that the end user can easily understand its theory of operation, performance, installation and maintenance for the product. All documents shall be submitted being filed in order to approve of GECOL and reorder later. Language in all documents and drawings shall be written in English and dimensions shall be used in metric SI-units. 12 Warranty The supplier shall provide a full three-year limited warranty on all equipment supplied. The warranty shall cover all parts and all costs, which are directly attributable to the 29/38

30 supplier. Warranty coverage shall begin on the date that the equipment is received. 30/38

31 Annex A Technical Data Sheet No. Description Particulars A B C General Manufacturer Total Mass (kg) Overall dimensions: Height ( mm ) Length ( mm ) Width ( mm ) HV Compartment Temperature class Ratings and characteristics a) Rated voltage b) Rated insulation level c) Rated frequency d) Rated normal current e) Rated breaking current - Active load current - Closed loop current - Transformer off-load current - Cable charging current f) Rated short-circuit making current g) Rated duration of short-circuit Gas pressure and limits of gas pressure Minimum clearances in air a) Between poles b) To earth Transformer Compartment Manufacturer s name Conservator or sealed type Rated power (kva) Rated voltage (kv) Signature : 31/38

32 Technical Data Sheet No. Description Particulars Rated voltage ratio at principal tapping (kv/v) Method of cooling Vector Group Off circuit tapping range Core a) Maximum flux density at nominal voltage and frequency (Tesla) b) Thickness of lamination (mm) Winding a) Material of HV winding b) Material of LV winding Short circuit impedance a) At principal tapping & rated frequency (%) b) At highest tapping & rated frequency (%) c) At lowest tapping & rated frequency (%) Maximum temp. rise at rated full loading: a) Oil ( ) b) Winding ( ) Short circuit duration (Sec.) Losses a) No load loss at rated voltage & frequency (W) b) Load loss at rated voltage and tapping, on full load at 75 (W) No load current (%) Voltage variation a) At 0.8 P.F. lagging (%) b) At 1.0 P.F (%) Efficiency a) 100% load at 1.0 P.F. (%) b) 100% load at 0.8 P.F. (%) Sound level (db) Insulation level a) Power frequency test voltage (kv rms) b) Impulse test voltage (kv peak) Signature : 32/38

33 Technical Data Sheet No. Description Particulars Tank a) Material of tank b) Tank finish method Thickness of tank plate a) Sides ( mm ), Bottom ( mm ), Top ( mm ), Radiator ( mm ) b) Max. pressure tank can sustain (kg/ cm2 ) Tank finish a) Type of paint applied internally b) Type of paint applied externally c) Color of tank d) Thickness of coating ( μm ) Gasket a) Material b) Thickness (mm) Over pressure relief valve (if any) a) Venting pressure ( kg / cm2 ) D b) Venting quantity ( m3 /min.) Insulation oil a) Mass of oil (Kg) b) Oil grade and standard specification adopted Mass of transformer (kg) Overall dimensions: Height ( mm ) Length ( mm ) Width ( mm ) LV Compartment Manufacturer Temperature class 33/38

34 Ratings and characteristics a) Rated operational voltage b) Rated insulation level c) Rated frequency Signature : Technical Data Sheet No. Description Particulars 34/38

35 4 5 6 E Busbar a) Number of busbar b) Rated current c) Rated short-time withstand current d) Rated peak withstand current MCCB for incoming a) Rated current b) Frame size c) Number of poles d) Trip method (Thermal, Electronic, etc) e) Dimensions of enclosure (HeightⅹWidthⅹDepth) MCCB for outgoing a) Rated current b) Frame size c) Number of poles d) Trip method (Thermal, Electronic, etc) e) Dimensions of enclosure (HeightⅹWidthⅹDepth) Enclosure Material Thickness of enclosure plate: Sides ( mm ), Bottom ( mm ), Top ( mm ) Thickness of coating ( μm ) Color / IP Painting method Signature : Designation : Name of Tenderer : Date : 35/38

36 Annex B Simple concept of the CB tripped by tripping coil with LV fuse 1. Linked with ZCT ZCT CB Trip coil Fuse Note 1: The rated current of the fuse shall depend on the rated secondary current of the ZCT and the rated current of the fuse shall be stated by the supplier. Note 2: The ZCT shall be in compliance with the GES titled Zero-phase-sequence Current Transformers. 2. Linked with 3 CTs CTs CB Trip coil Fuse Trip coil Fuse Trip coil Fuse Note 3: The rated current of the fuse shall depend on the rated secondary current of the CTs and the rated current of the fuse shall be stated by the supplier. Note 4: The CTs shall be in compliance with the GES titled Current Transformers. Note 5: The fuse and the trip coil for neutral line of CTs can also apply. 36/38

37 Annex C Interfaces for connection between RMU and cable For 630 A For 400 A For 200 A Dia 56± 0.2 Dia 56± 0.2 Dia 46± 0.2 Dia 46± 0.2 Dia 44.5± 0.2 Dia 25 min M16x2-6H Dia Dia 32.5± 0.2 Dia 30.9± min Dia ± ± ± 1 12± ± 0.2 Dia 48.5± 0.2 Dia 70± 0.2 Dia 70± 0.2

38 Annex D Single Line Diagram of Package Transformer HV feeder #1 HV feeder #2 ES ES LBS LBS HV Compartments (Similar to RMU) CB Transformer Transformer Compartments MCCB 1,600 A LV Compartments MCCB 400 A MCCB 400 A MCCB 400 A MCCB 400 A Note: The equivalent and better one can also acceptable.