We Have a vertical motor where the stator and the rotor both are totally immersed in dielectric oil. This morted shorted to ground. When the motor was removed and opened up we noticed that the bushings had picked up and alot of metal filings were in the oil. The centre lead, at its weak spot blew a hole in the lead and went to ground. The problem is that in the JB where these leads exit the oiled filled can the mounting studs are insulated from the steel can by an insulating bushing. The bushing on the phase that had the short was fine, the other 2 were burnt to a crisp!! Any ideas???
300 Hp 1800rpm
575 Volt
VFD driven
300 Hp 1800rpm
575 Volt
VFD driven
