Originally Posted by
Besoeker
I would assume that the nameplate figure of 32A is correct for that particular motor assuming it is a real motor.
Making typical assumptions for effy and pf that's about what I come up with.
However, the tables probably have to be conservative.
NEC wants us to use values in some tables within the NEC instead of nameplate for determining minimum ampacity for conductors and other motor calculations. The values in those tables are the worst case efficiency/power factor motors you would ever find.
The idea I think is if you replace say a 10 Hp motor with another 10 HP motor - you shouldn't need to worry about conductor size - it was already sized for worst case 10 HP motor you would ever encounter.
I live for today, I'm just a day behind.
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