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Wild_Bill Wild_Bill is offline
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Default Help understanding fan motor.

I've only seen external leads for the thermal protection device on
industrial motors (specifically Oriental Motors gearmotors).
The purpose of the external leads is for use where excessive motor heat
(overload) could be used to signal/actuate/interrupt other devices on a

So the TP (thermal protection) leads for your motor would be wired in series
with the L1 line-in, and one of the motor's power connections.
The other connection would be for N neutral.

The 2 identical readings between 3 wires would likely indicate the motor run
windings, and there should be ~132 ohms measured across the 2 windings in
series (end-to-end).
If there aren't 2 nearly identical resistance readings between windings
found, then those aren't likely to be the run windings (excluding
multi-speed connections).
BTW, there are no start windings in a PSC motor, only 2 run windings.

I haven't taken any resistance readings of PSC motor windings in a while, so
I can't say if the 66 ohm reading is reasonable.

I don't have any suggestions for the red and yel wires. My focus would be to
determine if the motor is useable, not all of it's features.

L1 o-----(switch)-----o(blk)--(TP)--(blk)o------(66R)------(center


Ground o---------------------------(motor case)

These would be the typical connections for a PSC motor, and how I would test
it, IF I were fairly certain of the run winding connections.

I would have separated the HV supply long ago, since it has no use in
powering the motor.

If it can be determined to be in working condition, then the possibility of
reversing the rotation may be considered.

FWIW, these motors can usually be found for ~$10 (maybe less) for a new
surplus motor with a wiring diagram and a specific RPM, from numerous
surplus dealers.


"when you pry it from my cold, dead hands" is the attitude of some folks
regarding "their" money.
But when the money is finally extracted, it has no value, because they've
squeezed all the ink out of the paper.

"Splork" wrote in message

OK, I looked at it again and took some readings that I did not before.
Black wire mystery is solved. Black in to black out is likely an
interrupter of
sorts. Thermal protection?? Allows the motor to cut power to everything
if it
senses trouble.

Zero ohms between them. Don't know how I missed that. If it is
failing (reason for discard), I can bypass it.

The gray wire to the brown is 66 ohms, increasing as we move towards
white, so
brown is the center tap and the start coil 66 ohms.

So the Black Wire hot out from the motor goes to the white lead, start/run
and HV input. Looks good. The other side of the HV input has the other
AC leg
and it would connect to the brown wire.

I presume whatever switching device is used, it would bypass (short) the
to yellow or brown to red or yellow to red or so on, to remove power to
coil segments. Something to ponder when I have a moment.

For hrhofann: Part number on unit is 001-02084-000
Ref # DM-60001
Year 04 H

Zilch on lookup by me. Got an idea?? I would love to see how this was
to be run.

Thanks guys!