Inverter duty motor terminals insulation
Inverter duty motor terminals insulation
(OP)
We received a special design inverter duty motor built to MG1, Part 31 with max voltage 460V (RMS). It has three phase terminals (bus adapters) with clearance through air and creepage distance between phases 0.5". It looks like the motor manufacturer has used RMS voltage rating for clearance selection. The motor insulation per MG1 Part 31 must be capable to withstand repeatable voltage spikes with the peak value up to 3 times line-to-line voltage, and the motor insulation should comply with that. My question is: should the terminal spacing be determined based on higher than RMS values, and is the existing clerance 0.5" adequate? Thanks in advance for your inputs.





RE: Inverter duty motor terminals insulation
RE: Inverter duty motor terminals insulation
RE: Inverter duty motor terminals insulation
MG1, 31.4.4.2 states:"... Motors with base rating voltage not exceeding 600V: Vpeak=3.1*Vrated".
Still, the question is: if the motor sees 1600V pulses, why spacing between terminals is selected for 460V RMS?
RE: Inverter duty motor terminals insulation
Now I would like an explanation since 3.1 times peak would be 3.1 x 660 = 2046.
Anybody out there that can clarify this?
RE: Inverter duty motor terminals insulation
RE: Inverter duty motor terminals insulation
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