SRI ® Make Extra High Voltage (EHV) Transformers << Back

Transformers with primary voltage of 66 kV and above are conventionally termed as Extra High Voltage (EHV) Transformers. These transformers are generally used in the transmission sector. We at Shri Ram Group Of Industries have facility to manufacture EHV transformer upto 50 mVA 132 kV class.

  • Technical Specifications
  • Salient Features
  • Standard Fittings
  • Optional Fittings

Technical Specifications

Rating Upto 50 mVA
Duty Type Outdoor/Indoor
Voltage Class 33, 66, 132 kV or as per customer’s requirement
No Of  Phases 3 phase
Frequency 50/60 Hz
Vector Group Dyn5 or Dyn11 or YNyn0 or as per customer's requirement
Insulating Fluid PCB FREE Mineral Oil, both inhibited & uninhibited, as per IS/IEC and customer requirement
Class Of Insulation Class A
Tap Changer Off Circuit or On Load
Tapping Range + 2.5% X 2 for OCTC or + 1.25% X 4 & -1.25% X 8 for OLTC or as per customer requirement
Winding Material Copper with multi paper covering
Applicable Standards IS 2006,IEC76,ANSI,IEEE
Painting Enamel, Epoxy, Polyurethane or customer specific

Salient Features of SRI ® Make EHV Transformers

Custom made to meet each and every requirement customers conforming to National & international Standards.
Designed by experienced expert engineers using most modern software.
Highest dielectric insulation property to withstand Lightening Impulse.
Permali wood clamping rings for uniform compression of primary and secondary windings.
Step lap core design with multiple sheets per bag used in the core lamination jointing.
Designed using advanced software like AutoCAD & ProE to ensure adherence to the design parameters.
Pre composed Insulation material for minimal moisture absorption.
In House Fabrication with Laser and CNC machines.
Facility to make 8-10 Transformers per month.


H.V. Bushing / L.V Bushing Conservator oil filling hole Bi- directional rollers
Earthing terminals pads Drain cum bottom filter valve Top filter valve with sampling plug
Plain Oil Level gauge Rating diagram plate Air release device
Thermometer Pocket Lifting Lugs Pressed Steel Radiators (Detachable)
Double Diaphragm Explosion Vent Silica gel breather Additional Neutral bushing
First filling of oil Isolating valves for radiator Jacking Pads
Dial type OTI with A/T contacts Buchholz relay with A/T contacts Marshalling box with control wiring

Optional Fittings

Dial type WTI with A/T contacts Magnetic Oil Gauge with A/T contacts On Load tap Changer
RTCC Panel with automatic voltage Regulator (AVR) Pressure Release valve DGPT Relay
Air cell bag Scada Compatible OTI & WTI Equaliser pipe between conservator & Explosion vent
Annunciators in RTCC panel Force cooling arrangement with Fan Cubical