We were servicing a 4160 to 480 1500KVA pad mount xformer, and when we turned the power back on an operator had left the control switch for a 200 HP motor in the hand position (no PB, just a HOA) and when my helper slammed in the second cut out, the motor went to single phasing and the noise the 4160 overhead started making was intense. It seemed to travel down the overhead distribution lines untill the breaker tripped. Never before or after have I heard a sound quite like that.
