MAINTENANCE/ REPAIR/ REPLACEMENT OF EXTERNAL ELECTRIC SUPPLY INSTALLATIONS, TRANFORMERS, TWO/ FOUR POLE STRUCTURES, VCBS, HT PANELS, HT/LT CABLE AND HT GOD SWITCHES INCLUDING PREVENTIVE MAINTENNACE AND ALLIED WORKS AT NAVAL BASE PORBANDAR UNDER GE (

M & L for general maintainance of 11 KV VCB's of different capacities and comprising the following: Disconnecting and dismantling the existing indoor type, 11 KV horizontal draw out type VCB trolly of rupturing capacity 250/350 MVA, 400/630/800/1000 Amps from location and repair /overhauling and carrying out with the following and all as specified and directed by Engineer-in-Charge. (Note: spare parts will be measured & paid seperately.) (a) Inspecting / overhauling of manual / motorised spring drive mechanism by checking mechanism, motor and gear assembly, big gear assembly, stop bolt assembly, main shaft interlocking assembly, closing spring assembly, small cam with screw,motor cut -off limit switch, butter fly switch assembly and apply multi grease lubricant to function smoothly. (b) Inspecting / overhauling of earthfault release assembly, tripping coil, auxilary switch etc and checking of electrical wiring system. (c) Calebration & Testing of over current & Earth fault relay by primary & secondary ejection methods. (d) Insulating of VCB track, greasing of wheel and checking for few movement for closing and withdrawing of VCB track. Inspecting / overhauling /cleaning power pack unit/battery bank such that in normal condition,VCB Control Circuit shall be operated by 110 V DC (e) Cleaning/wiping the insulating components, primary & secondary circuits i.e green spots, carbon deposited completely. Inspecting / overhauling /cleaning and inspecting through insulators, vacuum interupters by carbon cleaner solution and apply dry graphite conductive sealant for electrical contacts to avoid carbon deposits on contact surfaces. (f) Testing of primary & secondary circuit with 1000 Volts megger for insulation resistance. (g) Flash testing of secondary circuit at 2000Volts for one minute after disconnecting the instruments from the panel. Assembling all items/components parts to the respective postion after high voltage test complete. (h) Testing, sychronisation / calibration of meters and relays. (i) Cleaning/wiping of busbar, phase barriers, Busbar support and sleeves. (j) Scraping & painting the VCB with approved quality of grey paint all as directed by Engineer-in- Charge.

Dehydration of tranformer oil, obtained from transformers/voltage stabilizer etc. Dielctric strength shall not be less than 60 KV in 2.5 mm gap electrode after dehydration. Dehydration of transformer shall be carried out by using electrically operated dehydration machine including replacement of unserviceable silica gel and toping up/ replacement of unserviceable transformer oil complete all as directed. (NOTE :-- 1) Silica gel & new tranformer oil for top up shall be measured and paid against respective item. 2) Filteration of transformer oil shall be off loaded position of transformer.

Supply and filling transformer oil of approved quality ISI marked for filling in transformer for topping up/ replacement complete all as directed by Engr-In-Charge. Make: power/castrol/servo/asian/savita/electric. Note:-(i) Dielectric strength of transformer oil not less than 60 KV with 2.5mm gap. (ii) New oil which is to be supplied for filling should be in a sealed barrel/container only.

Supply and fixing in repair of breather with 500 Grams silica gel for transformer upto 400 KVA, all as specified and directed by Engineer-in-Charge.

Taking of old silica Gel for dehydrating Breather of transformer, cleaning the breather internally and externally and filling new silica gel blue colour in dehydrating breather.

M & L for spray painting of transformers (any type power or distribution)) of capacity upto and including 100 to 630 kVA ( in situ ) outdoor/indoor type, installed and located at different sites in scattered area under the GE including the following: - (a) preparation of old surfaces by cleaning, scrapping, rubbing/ polishing etc. complete. (b) Spray painting with two coats of synthetic enamel paint of approved make / quality all as directed at site. (c) Writing the SM MES No of transformer on MS body of transformer all as directed .

Supply and fix in repair/replacement industrial type temperature gauge of range 0⁰ to 200⁰C for indication of temperature rise in transformer oil for transformers upto 630 kVA capacity including taking out old unsv complete all as specified..

Material and Labour for disconnection of both HT and LT connection from cable and box, taking down the disconnected transformer (Outdoor/indoor type) upto 630 KVA capacity 11/.433 KV, installed at different substation and transporation of unserviceable transformer complete unit to the Transformer repairing workshop and reinstallation the same after repaired back including arrangement of necessary T & P crane and vehicle etc for loading/unloading and to carry following work (i) Draining out transformer oil, taking down HT/LT studs and opening the top cover to checking of windings. (ii) Desludging of core and coil assembly by hot oil pressure and checking/testing of all accessories to identify fault leve. (iii) Brazing of burnt/disconnected copper wound surfaces, studs and connectors including replacement of unserviceable bolts, refixing of existing serviceable bolts, nuts, washers of different size and tightening properly. (iv) Replacement of all gasket materials in top cover , HT, LT bushing using rubberized gasket sheet 4.0/6.0 mm thick duly paster with gasket cement including replacement of LT/HT coils. (v) Repositioning of core and winding assembly inside the tank, assembling the complete unit and re-filling of old transformer oil and top up with new transformer oil including oil filtration and testing. (vi) After assembly of complete unit of transformer load testing, insulation testing including all testing shall be carried out as per IEC and IS and test certificate shall be submitted complete all as specified and directed by Engineer-in-Charge. Note : Transformer oil and copper windings if required shall be measured and paid separately under relevant items of the schedule.

Supply only LT leg coil of copper windings with EC grade for transformer of capacity up to 630 KVA complete with insulation, varnishing by vacuum impregnation and baking of coil assembly, etc. complete all as specified & directed by the Engineer-in-Charge.

Supply only HT leg coil of copper windings with EC grade for transformer of capacity up to 630 KVA complete with insulation, varnishing by vacuum impregnation and baking of coil assembly, etc. complete all as specified & directed by the Engineer-in-Charge.