On 09:31:38 13th February 2007, ground fault through the human occurred during rectification work on the earth switch inside the voltage transformer compartment of the 6.6 KV incomer ¿B¿. The technicians have isolated the Circuit breaker of the 6.6kV Incomer B (secondary of the main ¿B¿ transformer) and then tried the earth switch which did not close. Then they opened the 6.6kV voltage transformer cabinet door overlooking the isolation of 33KV primary of the transformer. After racking out the Voltage Transformer, the person approached inside the cabinet compartment of incomer B to rectify the Earth Switch mechanism while the bus was live and the accident took place.