Meggars and Measurements

I'd use the procedure specified in the operator's manual.

Really, you do have the manual, don't you?

Maybe you could search for the model # of your particular machine if you don't.

I do not disconnect the wires of the supply cable in the motor's contact box if, for instance, I have to make a "high pot" test (against earth) of an induction motor which has only one set of windings and there are only 3 leads. If I measured "near to infinity" resisatance I am satisfied and if the mechanic I am with disapproves my procedure saying "According to rules, you need to disconnect the supply leads in the box", I leave him the pleasure of turning the nuts, upon what, having repeated the test, I report to him, now satisfied too, again "near to infinity."

But, caution: only if contactor(s) are used, not a soft starter (the more so a VFD) !

But you sure do disconnect the supply, don't you??

thank you all, but it would be nicer if u be more precise would'nt it.