FAULTS OF TRANSFORMERS:

Different type of faults that occur in transformers are below:-

Transformer



  1. EXTERNAL FAULTS:- The appearance of over current for a short duration or short-circuit outside of the transformer.
  2. INTERNAL FAULTS:- 


  • Terminal faults.
  • Incipient faults.
  • Winding faults.

Terminal Faults:- 

  • HV or LV terminals phase to phase fault
  • HV or LV terminals phase to earth fault
  • HV or LV terminals three phase faults

Incipient Faults:- This faults causes overheating and can consequently prove to be hazardous if not attended in time.

  • Core faults occurring due to the breakdown of insulation of the lamination, of bolts or of clamping rings, which may cause limited arcing inside the oil.
  • Earth faults occurring very near the neutral point of the star connected transformer.
  • Poor electrical connection of conductors.
  • Cooling system failure.
  • Improper oil flow.
  • Regulator failure and improper load sharing between transformers operating in parallel, thereby causing a circulating current.

Winding Faults:- 

  • HV or LV winding phase to phase fault.
  • HV or LV winding phase to earth fault.
  • Shor-circuit between turns of HV or LV windings.
  • Short-circuit between turns of tertiary windings.
  • Earth fault on tertiary winding.