Proctologically Violated©® wrote:

Awl--

Got a 10 hp Baldor up and running--someone had misread the numbering on the
wires, and thus miswired the motor--blowing fuses like crazy.

Inyway, I amprobed it, and a 5 hp Magnatek. Would you believe the 5 hp
Magnatek, no load, draws substantially more current than the Baldor???
About 20-30% more. wow....
I don't know if that's because the Mag is really piggy, the Baldor
super-efficient, or both.


An Amprobe is meaningless, without knowing the power factor. The
magnetek could
actually be drawing less POWER, even though the line current is higher.

The Mag, however, seems to have better bearings, as it spins quite a bit
longer w/o power.

Also noticed wide variations in the current draw of each leg (both motors).
For example, I read 3A on one leg, 9A on the other, 12 A on the third,
operating off an rpc. Is that normal?

It means your RPC is not balanced.

In NYC-supplied 3 ph, I seem to remember identical current draws on each leg
of a 3 ph motor (208 V).


Utility 3-phase is usually very well balanced, so no surprise.

Jon