All transformers are robustly constructed with premium grade raw materials. They are capable of satisfactory operations in the Tropics, in humid atmospheric conditions without deterioration. The workmanship is of highest standard and the entire construction is in accordance with the best modern practice. Utmost care is taken while manufacturing and assembling each and every component of a transformer.

The general process line of a transformer is :

Core

The Core is constructed from Lamination of imported Cold Rolled Grain Oriented (CRGO) low loss Silicon Steel. The core is braced by a structure made of reinforced steel Channels. It is pressed tight with even pressure over the whole of laminations to prevent undue vibration and noise. The core legs are securely bound with heavy duty insulating tape and the yokes are firmly clamped. The yoke and limb bolts are insulated from the sheets by means of Bakelite tubes which are tested to withstand 3 KV.

<

Windings

The Winding conductors are high conductivity aluminium/copper wires or strips insulated with multiple layers of crosslapped cable paper/enamel. Multilayer helical windings, sectional windings with or without radial canals and continuous windings are adopted depending on the voltage, current and insulation strength needed. Adequate radial or axial ducts, wherever necessary, are provided in the winding to permit oil circulation and to prevent formation of hot spots. This ensures that the rate of insulation deterioration is minimized and high life expectancy is achieved.

Assembly and winding Connection

The coils are axially supported by impregnated permawood, Pre-compressed Press Board spacers kept pressed by means of pressing rings. Adequate clearance and creepage distance between the limbs and windings are maintained. Tapping and Phase leads are run in Fibre/SRBP tubes separated from each other by adequate barriers. These tubes are rigidly braced to ensure that required clearance from coil to tank is being maintained.

Insulation and Impregnation

The principal component of insulation is insulating Pre-Compressed Press Board. The components like rings, duct, dovetailed spacers, blocks etc. are put under compression alongwith the coil assembly for pre-shrinking. Providing additional insulation compensates the slight recovery in dimensions after the pre-shrinking. This reduces the probability of coils getting loose during operation and also minimizes destructive circuit forces.

Terminals

Suitable Bushings, normally of solid porcelain type are fixed on to the cover or side by a clamping ring and bolts welded on the cover or side. Cable Boxes on High Voltage or Low Voltage sides are provided on request.

Tank

All tanks are fabricated from mild steel sheets of adequate thickness and are robust. Elliptical Tube/ Pressed Steel Radiators are generally used for heat dissipation. For smaller ratings radiators are integrally welded whereas for higher ratings they are of detachable type. Tanks are shot blasted to obtain quality finish and a coat of primer is immediately applied. After priming all tanks receive a coat of intermediate paint and after pressure testing they receive a final coat of paint applied by spray.

Transformer Oil

The transformers are filled with filtered and tested transformer oil supplied by reputed manufacturers. The two basic functions of transformer oil are Cooling and Insulating. Low Viscosity Oil is used to ensure dissipation of heat generated during operations. The transformer oil is filtered before filling in transformer to enhance dielectric value and to prevent arcing between two conductors of high potential difference.

Testing

A series of stringent quality control tests endow our transformers with operational reliability and long life. The intermediary and final inspection comprise of a large number of routine tests in accordance with national and international standards using precision grade instruments. A Test Certificate is furnished for each and every transformer.