Home  |  About Us  |  Query  |  Contact Us  |  Products |  Auxiliaries



SUís Transformer are designed, manufactured and tested to high standards. The raw materials are subjected to strict inspection and components are checked at every stage of manufacturing.

Every transformer is subjected to rigorous in house tests.

Our systematic quality assurance and working methods are guarantee of reliable transformer from SU. The transformers are fully backed by an efficient and prompt after sale service.


SUís magnetic circuit or transformers made of thin sheets of cold rolled grain oriented silicon sheets of cold rolled grain oriented silicon steel, insulated with the Carlit, having extremely low losses. In house cutting, metering and annealing of the lamination guarantee great reliability of magnetic circuit. SU design magnetic circuit of transformer for minimum core losses and magnetic current.

The winding along with the insulation forms part of electric circuit of transformer. SU design winding and insulation to with stand the stresses due to electrostatic forces, magnetic forces and temperature rise in normal conditions and over voltage under incidence of surges, when these stresses are several hundred times.

The windings are cylindrical and arrange concentrically. They are made of insulated electrolytic copper or aluminum conductor. SU transformer winding are either of copper or aluminum as the requirement of customer below 315 KVA and from 315 KVA of copper only.

SU transformer has reliable insulation of winding and current carrying parts of transformer from one another and from earthed parts. The axial oil duct are provided between the LV winding & core and between the HV and LV winding. The radial oil ducts are between the end of coils & core yoke and between the coils. The oil duct provides the path for oil circulation with direct cooling of all conductors, minimizing the hot spot temperature ensuring long life of transformer.

A special attention is given on the insulation and the cross section area of the leads and various parts. The frames made of Bakelite properly support the leads to withstand the mechanical stresses. The LV leads connections are of copper plate.

The oil from a very significant part of the transformer and has the important function of acting as an insulation as well as a coolant to dissipate heat losses.

So, SU uses the high quality of transformer oil with adequate quantity to create higher level of insulation in conjunction with insulated conductor and coils and also to provide a cooling medium capable of extracting quantities of heat without deterioration as insulation medium.

SU provide Off Load Tap Charger or On Load Tap Changer as the requirement of the requirement of the customer on the HV winding to control the voltage. Generally five tapings are provided on HV winding of range +-2.5% and +-5%.

The tanks are made of mild steel. All the parts-plates, hosting lugs, shapes etc, are welded to ensure great mechanical strength and absolute tightness. The tank is fitted with radiators for efficient cooling. Covers are suitably titled to avoid rainwater. They are bolted to the tank flange with packing of Gasket strip. Conservator is mounted on the cover for expansion of oil due to temperature rise. The tanks are carefully cleaned. The interior side of tank is painted with oil and heat resistant paint red oxide primer is applied and then three coats of weatherproof paint are applied.

All tanks undergo oil pressure test and vacuum test to avoid leakage of oil.

The tanks are fabricated rugged and tough to perform both outdoor duties under extreme temperature and indoor duties to room temperature.

For all sealing purpose to avoid oil leakage at joints, gasket and molded component made from neoprene bonded cork sheet are used which are heat and oil resistant and does not spreads, cracks and damages on compression.