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SRI ® Make V.P.I. Dry Type Distribution Transformers

Dry type transformers are those transformers that use air as cooling and dielectric medium instead of conventional technology of transformers which uses mineral oil as a cooling and dielectric medium.

Vacuum Pressure Impregnated (V.P.I.) Dry Type Distribution Transformers

V.P.I. is a process which is a step above the conventional vacuum system. V.P.I. includes pressure in addition to vacuum, thus assuring good penetration of the varnish in the coil. The result is improved mechanical strength and electrical properties. These transformers are used in installations within the building premises,crowded and urban areas,overloaded feeders, near to the load centre or even outdoors where there is oil theft.

We at Shri Ram Group Of Industries utilise a state of art vacuum impregnating system to manufacture Dry type transformers upto 3 mVA 33kV Class.


Rating Upto 3mVA
Duty Type Outdoor/Indoor, Ground Mounted Type& Pole Mounted Type
Voltage Class Upto 33Kv
No Of Phases 3 phase
Frequency 50/60 Hz
Vector Group Dyn1 or Dyn5 or Drn11 or any specific
Class Of Insulation F , H Or C class as required
Insulating Material Nomex, Silicone Varnish, Fiber Glass, Glass Epoxy
Class Of Insulation Class A
Tap Changer Off Circuit or On Load
Temperature Rise 65.C to 115.C above ambient temperature of 50.C by resistance method or as per customer’s requirement
Tap Changer Off Circuit or On Load
Tapping Range +-2.5% X 2 for OCTC or +-2.5% X 2 & -2.5% X6 for OLTC as per customer requirement
Winding Material Aluminum Or Copper with multi paper NOMEX covering
Applicable Standards IS 11171,IEC 60726
Enclosure Painting Powder Coated with RAL 7032 Shade or as per customer requirement
Tank Hermetically Sealed, Corrugated Type or Conventional Air cooled Type