In article ,
says...
"PrecisionMachinisT" wrote in message
...
On PSC, both windings stay energized when running, though once
started, the motor will continue to commute on lifting of power
from either winding--you just wont get but near to 1/2 the horsepower
out of it is all.

Ok, that seems to make sense, although the one winding can barely keep the
motor spinning once started together (it won't even spin up starting by
hand). It seems to run just fine with the two windings together, perhaps
the capacitor is internally connected in series? Begs the question of why I
have three wires, but, that's why I'm here.


I can't completely follow the information you've given, but
I can think of three possible connections for a PSC motor
with three external leads and an internal cap.

This one makes the most sense for a non-reversible motor
and, if I understand you, seems to agree with the impedance
readings you gave. Red & black tied to hot, white to
neutral

|--B--|(---/\/\/\/\--|
L----| |
|--R----/\/\/\/\-----|
|
N-------W-----------------|

This looks like another possibility, but requires 4 leads
exiting from the windings, where in the previous example
the windings' common could be connected internally. Same
power connection as above.

|--|(--/\/\/\/\--|
W--| |
|--/\/\/\/\--| |
| |
R---------------| |
|
B-------------------|

This is a common connection for a reversible PSC motor
where the two windings are the same. Neutral to white, hot
to *either* black or red, depending on rotation. This
doesn't agree with your measured impedances.

R---------|
|
B--|--|(--|--/\/\/\/\--|
| |
|---------/\/\/\/\--|
|
W----------------------|

Ned Simmons