REPAIR MAINTENANCE OF HT VCB PANELS AND CONNECTED ITEMS INLUDING CALIBRATION OF RELAYS IN DOLPHIN AREA UNDER AGE E M NO I OF GE UTILITY I VISAKHAPATNAM

Amount

M&L for replacement of damaged space heater in HT VCB 11 KV with new one suitable to operate on 220 Volts AC supply complete with necessary wiring and control cable with toggle switch and all as directed by Engr-in-charge.

Dismantling Existing earthing and providing new maintenance free Chemical earthing complete with 40mm x 3000mm Advance Chemical Earthing Pipe with (Strip in Pipe Technology) with 50 Kgs of Back Fill Compound buried directly in ground (Rocky soil) with earth pit not less than 2.5 Mtr deep below the normal ground level with top edge of plate not less than1.5 Mtr below normal GL connected to GI strip 25x6mm as earth strip by means of SS bolts,nuts,check nuts and washers all as per IS 3043-1987 all as specified or indicated including testing on completion and as directed. The earth resistance shall be measured using fall of potential method as per para 37 of IS:3043 & Combined resistance should be less than 1 Ohms. Note:-The unit rate shall be deemed to include for Excavation & earth work in any type of soil,PCC (1:3:6) type Chamber,RCC 1:2:4 type B-1 cover 50 mm thick reinforced with 8mm dia CTD bars@75mm c/c both ways, MS handle 12mm dia and funnel.

Construction of ring earth by providing multiple earth pits i) Wherever it is not possible to achieve required earth resistance with one earth electrode/pit due to difficult/rocky soil conditions, provision of ring earth consisting of more than one earth pit shall be done. The number of pits required shall be decided based on the resistance achieved for the earth pits already installed. The procedure mentioned above for one earth pit shall be repeated for other earth pits. ii) The distance between two successive earth electrodes shall be min. 3mtrs / length of electrode which ever is higher. and max. up to twice the length of the earth electrode. iii) These earth pits shall then be inter linked using 25X6 mm GI strip to form a loop preferably using exothermic welding or with the help of at least two number of stainless steel nut bolts of appropriate size. iv) The interconnecting strip shall be buried no less than 600mm (0.6m) below the ground level. This interconnecting strip shall also be covered with earth enhancing compound.

Measure the earth resistance as per IS 3043:1987 code of practice. Earth resistance value shall be less than 1 ohm in non-rocky/non-sandy surface by single electrode Installation and in rocky surface by multiple electrode installation (not more than three electrodes & its individual earth pits). For earthing purpose, if solid rocky layer is found within 10 feet from ground level while digging the earth pit then it is considered rocky surface.

Collecting necessary required data & peak load details from IED of any type/Make from 11kV HT panel , Transformer/Feeder full load details during peak hours. Relay Setting Calculations & Co-Ordination Study. Unit Protection Setting of Transformers. Feeder wise settings has to be furnished & Report with Firm Recommendations to be submitted , Down Stream Power distribution (Complete 11 KV system) overall co-ordinations of time need to be achieved. Disconnecting IED of any type/Make from 11kV HT panel, cleaning the contacts , IED configuration , Calibration & Testing of all the measuring & protection elements at site. Testing of all the trip functions of the relays after final current settings by simulating fault current by CT secondary injection test set , rectification of defects in control wiring for proper tripping of CB during actual system fault conduction through relay & Tripping coil in all as specified and as directed.

Note: The Contractor has to arrange necessary testing Kits, testing equipments, tools etc. Rental rates for the testing/calibration kits & connected equipments are deemed to be included in the quoted rate. Testing & tuning shall be carried out onsite with testing equipments in presence of Engr-in-Charge by Qualified , Licenced personal and test results shall be signed both by the contractor and Engineer-in-Charge and kept on recordin to the satisfaction of the Department.

Decarburizing/cleaning complete 11kV HT Bus bar chamber with electrical connections, complete bus bar from the bus bar chamber , Cleaning with CTC and ensure proper decarburizing up to proper megger value , refixing the same after applying Backtol Red solution to the bus bar insulator & checking all the connections , tightening the nuts , bolts complete incl replacement of defective rusted bolts & nuts all as specified and directed.

Control Wiring up to Control Chamber with 1 Core, 2.5 Sq mm Copper cable with proper ferules & appropriate Lugs.

Material and labour for provision of earthmat laid in trenches/ducts/walls/Roof Top made of following sizes of GI strips including jointing by means of riveting and brazing complete as required and directed. Make : Tata/Jindal

a) GI Flat 25 x 6 mm

ABB make UNIGEAR ZS1 BREAKER SPARES:-

BUSINES(1250A)25KA FOR UNIGER CUBICLE

INTERMEDIATE BUSHING TOP SIDE

END COVER FOR SHROUD,2//D-SHAPE BUSBARS

RUBBER RING

BUSHING

VACCUME INTERUPTER

TULIP CONTACTS

CTs epoxy cast wound primary CTs with minimum primary current 50 to 400 A, single/ double ratio, double core (Protection core-5P10 & Metering core- Class 1.0), 25 KA for 1 sec of 15 VA minimum Burden.

Shutter assembly

Tripping coil 110 V DC

Closing coil 110 V DC

Hinge Assly

Handle Unigear

Spring Charge Motor

BUS PT PANEL:-

(a) Contact Arm

(b) PT Trolly Spares

Auxiliary contactor

LED Indication Lamps

M&L for repairs/servicing of 12 KV outdoor RMU's of any make with mechanism comprising of the following:- (a) Cleaning of RMU for dust, oxidising and decarbonising with CTC. (b) Repair/servicing of spring loaded operating mechanism. (c) Repair/servicing of spring charging motor. (d) Checking, repairing & servicing of gearbox, auxiliary switches, spring, limit switch etc complete. (e) Checking & repairing electrical and mechanical operations (f) Lubrication all moving parts with petroleum jelly & cleaning all bushing insulators with CTC (g) Tightening of all mechanical connections of mechanism (h) Proper Tightening all LV connection of VCB.

M&L for repairs/servicing of Battery Charger suitable for control DC circuit of 11 KV RMU's and required Input Voltage 230 V AC , Out Put DC voltage is 12 V DC / 29Amp including taking down old complete all as specified and directed by Engineer-in-Charge. Make: AMARA RAJA / EXIDE / AMARON

Supply, lay, connect, test and commission 3 Core 2.5 sqmm multi core copper conductor cables, XLPE insulated, LT 1100 volts grade GI strip/wire armoured in ducts/on structures including clamps, terminations on both ends with glands and connecting up to the equipment all as specified and directed. Make : Havells/KEI/Polycab.

MVV Prasad

JAI ENTERPRISES

SRIESWARI ENTERPRISES

P VENKATA RAO