The core is constructed from lamination of Cold Rolled Grain Oriented, low loss electrical sheet steel confirming to the latest International Standard which define its physical characteristics such as freedom from scale, degree of waviness, brittleness, tolerance on thickness, the inherent loss due to hysteresis and eddy currents, the permeability, and the methods to be employed to ensure compliance with the specification. Each lamination is coated with both sides with insulation which is unaffected by continuous operation in oil at temperatures normally experienced in Transformer service. The core, which is of interleaved construction, with mitered joint to reduce iron loss and magnetizing current, is designed to have a uniform flux distribution throughout the magnetic circuit.
Transformer winding are designed to meet three fundamental Requirements: mechanical, thermal and electrical. They are cylindrical in shape and are assembled concentrically. Paper insulated conductors of high conductivity soft drawn copper used, comply with the latest Indian Standard, both HV & LV winding are wound with adequate bracing and securing tapes in order to achieve a strong, self support structure. Insulation between layers and turns is based upon the impulse test level of the voltage class of winding as specified in IS 2026.
Tapping are brought away from the winding by means of flexible conductors, heavily insulated with paper, and supported by insulated tubes or cleats to prevent movement under service conditions.
All tank are fabricated from mild steel which is electrically welded, cooling radiators are welded or detachable depending on the size of the transformers. The cooling radiators are of pressed steel, electrically welded. AII tanks are pressure tested before leaving the fabrication shop of factory.
The Ovening of the transformer is carried out in well ventilated, electrically heated ovens for a period determined by electrical testes. The transformer is then fitted with dehydration oil confirming to I S 335.
Before dispatch, all transformers are subjected to routine tests in accordance with IS: 2026, or to such tests as the customers specification requires.
Energy Saving under non-liner loads:
Pollution of power systems is due to injection of harmonics under non-liner condition. These condition are found in case of pumping application, industrial application like thyristor drives, are furnaces, etc. Under such environment will have 5 time greater energy saving than CRGO core transformer.
The no load loss is a continuous loss taking place after energisation during the period of operation. In case of amorphous core transformer, no load losses are reduced by 75% when compared with conventional transformer. If we compared the marginally higher initial one pays with saving in the electricity bills, the pay beck in majority of the cases will not exceed 2/3 years. Annual energy savings. (Rs) = (NLL of CRGO – NLL of AMT) in Kw x 24(hrs) x 365 (days) x 4.5 per Khw