Repair and refurbishment of 12.5 MVA Transformer (6.6/132 kV) of Kulhal Power Station

Amount

Dismantling of the Transformer from its existing Location and Shifting upto Erection Bay

To & fro transportation: Loading –Unloading and packaging of 12.5 MVA transformer & its accessories from Kulhal Power Station to contractor’s workshop/warehouse including insurance(Transit Insurance) of the transformer during the work from reputed insurance company

Dismantling of core assembly:

Opening & removal of top cover plate and other accessories

Dismantling of core-coil assembly.

Replacement of existing Core with new one of same design & its Assembly with Winding, duly varnished with tests viz. Insulation Resistance and Ground Test etc. Core Specification: 1. Material and thickness of lamination: CRGO silicon steel (Nippon/POSCO/AK Steel), 0.27 mm 2. Material used for insulation the lamination: Carlite 3. Normal working induction density: 16700 lines/cm2

Replacement of HV & LV windings and assembly

Providing & Sizing of the new Copper Windings (HV and LV both) & new insulating materials. (Brand for conductor copper: Sterlite/Birla, Purity: 99.99%)

Assembly of new windings with all new insulating materials over the new core.

Making connection including leads, tap leads, soldering, brazing etc.

Dry out of Core –coil Assembly: Drying out of complete Core-coil assembly to achieve proper IR values and Tan Delta Values

Tanking of core –coil assembly

Overhauling & Replacement of accessories:

Replacement of WTI with measuring CT (Make : Precimeasure or equilent)

Replacement of OTI((Make : Precimeasure or equilent)

SITC of LV bushings with New Rod and Nuts(Make : CJI Porcelain or equilent)

Replacement of all Gaskets & seals etc. by new one

Replacement of Breather with blue Silica Gel

Replacement of Membrane of Vent Pipe of same size and material

Replacement of Bucholtz Relay and Replacement of MOLG

SITC of Neutral Bushing (Make : CJI Porcelain or equilent)

SITC of Neutral C.T. 60/1 Class Protection-PS, Burden-50 VA

SITC of Marshalling Box for Temp. Indicator (WTI and OTI both) & Auto/Manual Control Circuit for Cooling Fan with latest Protection

Replacement of all copper flexible (300 A) (min. 50 mmx5 mm)

SITC of HV condenser Bushing, 145 kV, 800 A, IEC 60137(Make: Toshiba/Alstom/Telk/Yash high voltage)

Replacement of Radiator Assy. 240 mm, 300 mm, 35Fins and its valves

SITC of Fans 24", 900 rpm, 3 phase, 415 Volt, IP-55 with Armoured Cable (04 No) (Brand of Fans: almonard/Crompton/alstom marathon)

Filtration and Filling fresh Transformer oil (IES-60296 Nephthanic base) approx. 8400 Ltr (Note: Transformer oil shall be supplied by the contractor). The old oil approx. 8400 ltr. of the transformer shall be returned to the contractor.

Painting: Removal of old Paint and Repainting on entire Surface of transformer & accessories

Testing of the Transformer before dispatch to Kulhal HEP.

Erection of the transformer complete in all respect at Unit ‘C’ transformer bay of Kulhal Power Station by Contractor in presence of UJVNL officials.

Testing and Commissioning of the repaired 12.5 MVA, 6.6/132kV transformer as above on full load condition in presence of Expert.

Petty Misc. Work Like replacement of HT conductor (10 mtr. Each) of all Phases (if required), Modification in LV enclosure and Fabrication of LA voltage divider