Dehydration, installation, testing and commissioning of old and used GEC make 05 MVA, 132/33KV single phase transformer at 132KV S/s, Bhowali under 220KV OandM Division, PTCUL, Haldwani

Collection of fresh transformer oil drums from 220 KV substation Kamaluaganja, Haldwani (20 nos.) and 132 KV substation Kathgodam (5 nos.), their safe loading, transportation to 132 KV substation Bhowali and unloading at work site as per direction of engineer incharge including cost of all cartage, labour and T&P complete in all respect.

Draining out of old transformer oil from main tank, OLTC tank & radiators of old and used GEC make 5 MVA, 132/33 KV transformer, their safe storage in empty oil drums and other related works as per direction of engineer incharge including cost of all consumables, labour and T&P complete in all respect.

Safe and proper dehydration of old and used GEC make 5 MVA, 132/33 KV transformer by performing following standard activities as per direction of engineer incharge including cost of all material, highly skilled manpower and special T&P (Portable High Vaccum Machine, Dry Nitrogen Gas Cylinder with -60ºC dew point or better & purity 99.99% or better, Dry Air Generator Plant and Dew Point Meter, Heaters alongwith Enclosures for Controlling Heat Loss). (a) Complete leakage testing of main tank of old and used GEC make 5 MVA, 132/33 KV transformer. Execution of dryout cycles with the help of Portable High Vacuum Machine. Maintaining Vacuum <1.0 Torr for a minimum period of 48 Hrs. Measurement of vacuum shall be done with McLeod gauge/digital gauge. All material, labour and T&P including necessary arrangement like hose pipe of required length as per site condition for vacuum pulling has to be arrange by contractor. (b) After completion of vacuum cycle of 48 hrs, the vacuum break is to be achieved by nitrogen gas purging till the pressure of 0.2 Kg/cm2 is achieved and maintaining it for a minimum period of 24 hrs. After completion of 24 hrs with nitrogen gas pressure, the dew point of gas filled in the tank is to be measured and recorded. (c) Heating the transformer up to 60⁰C under N2 filled condition. (d) The vacuum for 48 hrs. and nitrogen gas purging for 24 hrs. becomes one cycle of dryout cycle. Minimum 2 dryout cycles shall be carried out till desired dew point of main tank is achieved. In the above dryout cycles, Dry Nitrogen gas cylinders (-60ºC dew point or better, purity 99.999% or better) shall be required for N2 purging and Contractor has to produce the test report of each dry nitrogen cylinder.

Safe and proper centrifuging of insulating oil of old and used GEC make 5 MVA, 132/33 KV transformer (quantity-approx 6 KL) by performing following activities as per the direction of engineer incharge including cost of all material, highly skilled manpower and special T&P (10-12 KL Transformer Oil Filteration Machine with Operator, Hose Pipes of required length, Oil Storage Tank of minimum 6 KL capacity with Oil Level Indicator and Breather arrangement filled with new silica gel & Comibrated PPM Kit). Complete replacement of all the gaskets of transformers is also to be done. (a) Sample testing of oil from drums for BDV & PPM before pouring into storage tank at site. (b) Sample testing of oil for BDV and PPM after completion of oil filtration in storage tank, before filling in transformer main tank. (c) Filling of transformer oil in main tank, OLTC & other accessories and complete assembly with prepared and tested oil under vacuum up to desired level. (d) Execution of Hot Oil Circulation Process and maintenance of temperature in tank up to 55°c for not less than 72 hrs to achieve desired insulation parameters of oil (BDV>70KV & PPM=<5). IR value has to be regularly recorded during the complete drying out process.

Collection of oil samples of transformer and its testing for DGA, PPM & BDV NABL approved laboratory preferavly from CPRI/PGCIL after completion of oil filtration work.

Safe and proper dismantling of defective BBL make 5 MVA, 132/33 KV transformer existing on plinth by stepwise dismantling of OLTC, conservator tank, radiators, bushing etc. as per direction of engineer incharge including cost of all material, labour and T&P complete in all respect.

Safe and proper dismantling of NIFPS system of defective BBL make 5 MVA, 132/33 KV transformer alongwith all accessories transformer and its accessories as per direction of engineer incharge including cost of all material, labour and T&P complete in all respect.

Safe and proper shifting of diffective BBL make 5 MVA, 132/33 KV transformer from plinth to safer place as per direction of engineer incharge including cost of all cartage, labour and T&P complete in all respect.

Safe and proper shifting of prepared GEC make 5 MVA, 132/33 KV transformer from store to plinth as per direction of engineer incharge including cost of all cartage, labour and T&P complete in all respect.

Safe and proper erection of GEC make 5 MVA, 132/33 KV transformer by installation of radiators, bushing, conservator tank etc. as per direction of engineer incharge including cost of all material, labour and T&P complete in all respect.

Safe and proper retrofittting of NIFPS system on GEC make 5 MVA, 132/33 KV transformer under supervision of OEM including cost of all material, labour and T&P complete in all respect.

Safe and proper rearrangement of HV, LV & TER Jumpers for connecting spare 5 MVA Transformer to 3×5 MVA Transformer Bank as per the direction of engineer incharge including cost of all material, labour and T&P complete in all respect.

Development of cable schedule and carrying outwork of cable laying all connections in marshalling boxes and NIFPS.

Complete pre-comissioning testing of 3×5 MVA Transformer such as open circuit, short circuit, vector group, stability, insuation test, winding resistance test, tan delta, SFRA etc. including testing of HV/LV side bay equipments as per direction of engineer incharge including cost of all material, labour and T&P complete in all respect and submission of test report in 3 copies jointly signed with O&M and T&C wings of PTCUL.

United Engineers