TKES
GO Insulation Types
PowerCore™ Grain Oriented Steel is usually delivered with a thin inorganic coating C5G applied on both surfaces, on top of the so called glass film layer formed during annealing. The coating thickness of 2-5 microns provides good electrical resistance simultaneously ensuring a high stacking factor. The stress relief annealing of wound cores or punched laminations, usually performed at temperature around 840°C. It is unaffected by, and in turn does not affect, the various types of oils used in transformers.
Insulation Type
Product CRGO
  C-5
Parameter C5(G)
Inorganic
AISI Class C5
Coating Type Phosphate Over Glass Film
Range of Application Power & Distribution Transformer
Colour Grey
Average Coating Thickness µm 3.5+/-1.5
Space Factor (%) / Stacking Factor >96.0
Typical Average Insulation Resistivity in Amps. 0.38
Typical Average Insulation Resistivity in Ω.cm²/La 10
Stress relief Annealing in Nature / Reducing Atmosphere Temperature at 800 Deg C Can Withstand
Corrosion Resistance Good
Resistance to organic solvent oil, lubricant oil & transformer oil Resist
  • 1 Colour Deviation is possible without effect of on coating properties
  • 2 Coating Thickness is checked by FISHER DELTASCOPE Coating Thickness Tester
  • 3 Space factor is checked in accordance, with IS 649:1997
  • 4 Insulation Resistivity is checked in accordance with IS 649:1997