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.

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?
In NYC-supplied 3 ph, I seem to remember identical current draws on each leg
of a 3 ph motor (208 V).
--
Mr. P.V.'d
formerly Droll Troll

Procto sez:

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

The current draws of commercial 3-phase and RPC's are not ever going to be
the same. This is because a RPC is, in reality, is an electrical network
comprised of both idler and load motors. I suggest you do a bit of study on
RPC's. There are good links on Google and Metal Web News.

Bob Swinney


"Proctologically Violated©®" wrote in message
...
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.

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?
--
Mr. P.V.'d
formerly Droll Troll

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