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OUR QUALITY ASSURANCE PLAN

DETAILS OF QUALITY CONTROL

A. RAW MATERIALS

  • Raw materials are received and inspected physically first and then tested for quality.
  • Raw materials are sorted out and stacked properly according to dimension.
  • C.R.G.O lamination received as per our design is checked for dimension, insulation and loss.
  • Conductors received as per our order are checked for insulation and dimensions.
  • Steel materials received from SAIL are checked for thickness and dimensions.
  • Transformer oil received in barrels is tested for BDV Value and Tandelta.
  • Insulation materials received from manufacturers are also tested for insulation resistance and quality.
  • Insulating papers are checked for strength and thickness.
  • All other ancillary materials are received and also checked according to relevant specification.


B. IN PROCESS

  • CRGO ASSEMBLY: CRGO lamination are assembled as per design, maintaining the required weight and core diameter.
  • CONDUCTOR: HT & LT coils made on HV & LV winding machine maintain the required inner & outer diameter, and the number of turns as per design.
  • COIL ASSEMBLY: HT & LT coils are assembled on CRGO assembly, maintaining the required clearances.
  • FABRICATION: Tank is manufactured as per design. Pressure test is conducted on the 100% manufactured tank with an air compressor to check for any welding leakage. The tank is then painted and measurement of painting thickness checked by elcometer at random.
  • BAKING: Baking of coil assembly performed at 120 °C to raise its insulation resistance value.
  • BOX–UP: After baking, the coil assembly is tanked. Transformer oil is then filled through a filter machine.


C. TESTING

I.FIRST STAGE
  • Random dimensional check of both HT & LT conductor before coil winding.
  • Random measurement of core thickness, length and width before CRGO assembly.
  • Random measurement of core diameter before coil assembly. Random dimensional measurement of tank before alignment and fitting.
  • Random dimensional measurement of tank before alignment and fitting.
  • 100% measurement of turns ratio-by-ratio meter before box-up process.
  • Random measurement of BDV of transformer oil from oil barrels.
  • 100% measurement of Insulation Resistance Value by MEGGER before oil filling in box-up process.

II.SECOND STAGE
  • All routine tests are performed as per IS 1180 & IS 2026.

ERDA TEST

Dynamic short circuit and impulse test conducted by Electrical Research and Development Association (ERDA), Vadodara, India for 16 kva, 25 kva, 63 kva, 100 kva, 200 kva, 250 kva, 315 kva and 500 kva (oil type). And also 3 star rating transformers for 63 kva, 100 kva, 160 kva & 200 kva.


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