Standard manufacturing practices

  • KPEL use only pre-compressed board material for insulation.
  • Axial and radial banding for sturdiness
  • Interleaved disc winding for 33 KV CLASS Transformers.
  • Layer type of winding for LV and HV coils for better impulse voltage distribution.
  • Proper distribution of clamping force for better clamping of windings.
  • Pre shrinkage of coil, smooth control of shrinkage force.
  • No further shrinkage of windings under short circuit forces in the system.
  • For core coil assembly, Pre compressed press board material/supreme grade insulating material is used.
  • Silver coated tap switches for high current transformers and linear tap switches.
  • Taps at winding middle for better ampere turn distribution and increased short circuit withstand.
Core Stacking in process
Static compression of winding
Defined routing of tap and line leads for better voltage distribution

Heat drying vacuum oven

The core and coil assembly with respective connections is dried in vacuum oven for a pre determined oven cycle based on insulation structure, At a vacuum level up to 1 torr@100C temperature, Which eliminates complete moisture from insulation material and also use of Micro processor based temperature for controller to record Temperature for controller to record Temperature v/s time for improvement of insulation resistance values.

Core Stacking in process

Tanking and Testing

The dried core coil assembly is boxed up in a pre fabricated M.S. Tank which is painted with a hot transformer oil resistant paint, The tanks are fabricated with mild steel procured from reputed firms.

Tanks are electrically welded with adequate sheet thickness and suitable stiffeners are provided to withstand operational and sudden pressures. Cooling is achieved by pressed steel radiators.

Tanks are short blasted before applying a premier coat of paint, External surface can also be zinc sprayed on request and sprayed with two coats of gray weather resistant, Epoxy finish paint highly resistant to chemicals and oil. Transformers can be hermetically sealed or breathing type with conservator.

The finished transformer is offered for routine testing as per relevant standards. All the transformers are routine tested with relevant standard/customer specifications are conducted. All the transformers are Pressure Tested at a positive pressure of 6 PSI for a period of 16 hours and the job is finished and kept ready for dispatch after application of final painting as per requirement.

step lap lamination built core