One of the apprentices at work was given a 3 phase motor to overhaul yesterday. It was off a tooling machine for a local car manufacturer so was covered in lubricating oil which had also penetrated to the inside the motor. Before we start dismantling we always do static tests, i.e. IR and phase resistance then visual check for any obvious signs of damage etc.
The Appo connected the earth lead to the motorbody and touched the terminal block with the other lead, as he pressed the button on the megger there was an almighty bang with a big cloud of smoke and he was splattered in oil and dust.
Has anyone ever heard of this type of thing happening before when using a megger? The only explanation I can think of is the oil, which was contaminated and filthy, had caused a build-up of some unknown gas and it had ignited when he pressed the test button.
The megger is model number BM223, just a basic megger/resisitance instrument with 250v/500v/1000v settings. He was using the 1,000v setting at the time. Any suggestions would be appreciated.
The Appo connected the earth lead to the motorbody and touched the terminal block with the other lead, as he pressed the button on the megger there was an almighty bang with a big cloud of smoke and he was splattered in oil and dust.
Has anyone ever heard of this type of thing happening before when using a megger? The only explanation I can think of is the oil, which was contaminated and filthy, had caused a build-up of some unknown gas and it had ignited when he pressed the test button.
The megger is model number BM223, just a basic megger/resisitance instrument with 250v/500v/1000v settings. He was using the 1,000v setting at the time. Any suggestions would be appreciated.