Nardie
Member
- Location
- North Augusta, SC USA
I have a three phase 10hp motor, that when we restarted today tripped the heaters within 10 seconds. The voltage system is a B-phase corner grounded delta system, which means that B-phase is grounded so there is no fuse installed for B-phase. We reset the heaters a few times, and tried to restart the fan. Each time the heaters tripped. We then checked continuity between the phases at the starter, and B-phase was open between the other phases. We also, megger tested at 500 VDC between each phase at the starter with the same results. We also checked B-phase to ground and determined there was no short. The plan tomorrow is to determ the conductors at the motor, and perform continuity and megger testing to determine if it the power conductors or motor is open. My initial evaluation based on the testing results, is that I have an open winding on the motor creating a single phasing situation. So does anybody have any other thoughts or testing recommendations. Thanks