Transmission Perspec..

Incident No.1 – Near Miss
• A 15MVA 132/33kV transformer was taken out of service
for a scheduled tap changer maintenance during a
weekend. When the maintenance was completed, the
transformer was re-commissioned and put back on load.
Minutes after taking load, smoke was seen coming out of
the diverter chamber of the transformer.
• The investigation revealed that the transition resistors
were heating the oil, because the resistors were
continually in the circuit due to incorrect wiring.