URJA is recognized as a leading and most reliable three phase cast resin dry type transformer manufacturer, supplier and exporter from India. Our cast resin dry type transformers comply with national as well as international standards such as IS 11171, IEC 60076-11, BS and CE. Also we use enclosure of IP55 Degree of Protection rating.
We manufacture cast resin dry type transformers up to 3.5 MVA and 33 kV Class. These transformers are air cooled.
Cast resin dry type transformers are used for indoor as well as outdoor applications. In these transformers, the complete encapsulation of primary and secondary winding in epoxy resin prevents penetration of moisture into windings. The cast resin offers very good protection against adverse ambient conditions. These transformers can work without disruption of service at 100% humidity. Due to the high grade insulation material, coils are non-hygroscopic & the transformer can be switched on directly without pre-drying even after a long period of service interruption. Contrary to the conventional dry type transformers the cast coil transformers are better in respect of impulse voltage withstand strength.
Higher dynamic short circuit withstands strength as compared to oil immersed and conventional dry type transformers because of fibre glass reinforced epoxy encapsulation. No partial discharges can occur during operation. The insulation material used is glass fibre reinforced with epoxy resin of class 'F' which can withstand wide temperature variation. Class ‘F’ insulating polyester resin can withstand hot spot temperature rise upto 145 Degrees Celsius and maximum winding temperature upto 180 Degrees Celsius. Due to high quality insulation material the transformer is practically non-inflammable by an electrical arc. Hence special fire protection measures are not required.
Encapsulation of coils with cast resin brings stability to the coils dimensions & no coil tightening is required to maintain the short circuit strength. Also no checking of oil level and electrical insulation/oil is required. This leads to saving in cost on account of maintenance. As cast resin transformers are solidly cast, problem associated with oil filled transformers like oil leakage and pilferage of oil is completely avoided.
These transformers are generally smaller in dimensions and lesser in weights. The construction and installation cost for the sub-station can be reduced by adopting dry type transformers. Without fire or danger of explosion, it is possible to place the transformers near to the load centre. Also, these transformers do not need construction of special fibre brick walls or oil pits, which reduces the overall civil works. Additionally, since LT cables are not required, there is also saving in cost on account of expensive cable laying works. Since no oil is used in these transformers, there are no chances of contamination of ground water due to oil leakage.
Application of Cast Resin Dry Type Transformer
These transformers are used in small and medium voltage distribution network for hotels, feeding basements or stilts of high-rise buildings, air ports, stadium, shopping malls, chemical, refinery plants and industries located in coastal regions.