Connection of HT and LT cables to transformer primary and secondary shall be under
the scope of the party. Lugs and nut bolts etc. required for connecting LT cables shall have
to be provided by the party.
The size of the existing foundation : (length)1360mm X (breadth)700 mm X (height)
The transformers will be checked for any defect / discrepancies in presence of OIL's
engineer and rectification of the same will be done to OIL's satisfaction by the party at their
After placement inside the substation the equipment will be grouted to the floor by
the party. Wheels of the transformer shall be locked in its final installed position.
All material required for earthing job as mentioned below shall be supplied and
installed by the party.
GI straps of 50x6mm size shall have to be provided for earthing of the transformers to
the existing earth electrodes. Earthing connections should be as per IS-3043.
Any excavation required for erection/replacement of the earth strips shall be under
the scope of the party.
C. COMMISSIONING OF TRANSFORMER
The following commissioning checks will be done on the transformer by the party.
Party shall have to commission the transformers one after another.
External earth and neutral point of the transformer should be properly connected to
two nos. of earth electrodes as per detail mentioned under EARTHING. Neutral shall have to be grounded by 2 nos. single core, 120sqmm PVC insulated cable(party shall have to provide the cable)
Remove inspection covers, check for any foreign object, clean the interior with dry
cloth or blower as required, check all the connections for specified tightness, check all the insulating supports for any damage, set tap links as per site requirement and fix-back the
Check insulation resistance and PI of HV (5.0kv megger) and LV (1.0kv megger)
windings. Their values should be as per manufacturer's recommendation. In case the transformer insulation needs drying up the same is to be done by the party as per
manufacturer's recommendation and to OIL's satisfaction at their own cost.
Check resistance of RTDs for three windings, their connections in the marshalling box.
All damaged or defective components must be replaced by the party at their own
cost with suitable replacement from the manufacturer.
In case the result of checks mentioned above are as per manufacture's pre-
commissioning check list and acceptable to OIL then the HV power cables and power
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