Wiring a new drum switch to my original MW motor

Hi Sayd, once you have performed Robert's tests above you need to phase the two run windings. One way to do that is to make two tests under power, connecting one run winding at a time in parallel with the start pair and noting the rotation. The goal is to be able to connect all three pairs in parallel, and each run winding connected to give the same rotation, rather than having the two run windings out of phase and fighting each other.
-Mark
 
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Robert and Mark -- thanks for the great guidance. I will run through this routine and report back with results (or more questions!) tomorrow.
 
Once you have identified the motor wires we can help you wire the drum switch- first things first
-Mark
 
And running the motor with only the START and one RUN winding at a time is better that the other method which Murphy's Law pretty much guarantees will exercise your circuit breaker.
 
wa5cab said:
First, make a safety check. I don't know what kind of ohmmeter you have so if any of the following steps can't be done, just skip them.
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I'm using a cheapie Craftsman multimeter.

Set the +/- switch to +
Set the mode to Ohms. Set the range to the highest value that the meter has, such as R X 10K
Connect the negative meter lead to the frame of the motor.
Momentarily touch the positive lead to the motor frame. Reading should be zero or near it.
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Performed this and got the expected result of zero.

Connect the positive lead to each of the 6 wires, one at a time. No wire should show less than Infinity.
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Performed this and got no continuity from the motor frame to any wire.

Connect the negative meter lead to 2. Connect the positive lead to the other wires, one at a time. Only one wire should show less than Infinity. Note the wire number and resistance reading. If necessary, temporarily switch the ohmmeter to a lower range in order to get an accurate reading. Switch it back to the highest range before proceeding to the next wire. If a second wire also showed continuity to 2, record that and the resistance. Note that one pair of wires (the START circuit) should show momentary resistance between the wires and return to infinity. If you find such a pair but it does not return to infinity, you have a bad start capacitor. Note that but carry on with the test. When all have been checked for continuity to 2, move the negative lead to C5 (unless it was the one connected to 2, in which case, skip it). Proceed to check and record the resistance between each of the remaining wires. Report results here.
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Alright, with negative connected to 2, I got:

Wire 6: zero
Wire 8: infinity
Wire C5: zero
Wire 7: infinity
Wire E: zero

Since this was a little different than what we expected, I ran the same exercise for all the wires, reported below.

Negative to C5, positive to:
Wire 6: zero
Wire 8: infinity
Wire 2: zero
Wire 7: infinity
Wire E: zero

Negative to 7, positive to:
Wire 6: inifinity
Wire E: infinity
Wire 2: infinity
Wire 8: down to 50 ohms then slowly climbed up from there towards infinity
Wire C5: infinity

Negative to 8, positive to:
Wire 6: infinity
Wire E: infinity
Wire 2: infinity
Wire C5: infinity
Wire 7: slow drop to zero, then slow climb towards infinity

Negative to E, positive to:
Wire 6: zero
Wire 8: infinity
Wire 2: zero
Wire 7: infinity
Wire C5: zero

Negative to 6, positive to:
Wire E: zero
Wire 8: infinity
Wire 2: zero
Wire 7: infinity
Wire C5: zero

So I've learned from your notes above that it looks like 7/8 would be my START circuit. I'll wait for further instructions! Thanks for this.

Zayd
 
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OK here's what I think is going on: 7 and 8 are indeed the start circuit, so that's good. As for the other readings I suspect you may have a short between windings, or the two run windings are connected in parallel already internally, which is seeming less likely since they brought out 4 wires. How low does your meter read on ohms? Does it have a Rx1 or Rx10 range? The run windings should measure something like 6 to 8 ohms each which in parallel would read 3 to 4 ohms or so. See if you can get some meaningful low ohm readings and report back

-Mark
Unfortunately, a new motor may be in your future
 
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markba633csi said:
OK here's what I think is going on: 7 and 8 are indeed the start circuit, so that's good. As for the other readings I suspect half of the zeros are true zero (connections) and half are low ohm readings thru the windings, so the two run windings are connected in parallel already internally. Why they brought 4 wires out I don't know yet. How low does your meter read on ohms? Does it have a Rx1 or Rx10 range?
-Mark
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Mark, I set it at 2000k for those readings. I can get down to 200 ohms. Should I repeat the exercise at that setting or are there specific wire combinations I should check?
 
I corrected my post after thinking about it for a while- you may have shorted run windings- try measuring again at the 200 ohm range and see if you can differentiate the zero readings. But the signs are not encouraging.
Be sure to re-zero your meter when you change ranges, and that the wires and test probes are clean and give stable readings
-M
 
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I'm afraid that Mark is correct. It ain't luckn gud. I guess that at this point I would repeat the check with the ohmmeter set to its lowest range.. But regardless of what you find, you or someone is going to have to pull the end bell off of the end with the wires coming out. And figure out what's going on. What you should be seeing (ignoring #7 and #8) is between one wire and two others, infinity. And between that one and the fourth wire, 4 to 8 ohms. Even if you find that you can differentiate between the wires that are tied together and the other two that are also tied together at the other ends of the two run windings, you would potentially be smoke testing your breaker to apply power to the motor.

If you feel comfortable with pulling the end bell, go ahead. If you don't, take it to a motor rewind shop and let them fix it.

Regardless, when it comes time to connect to the reversing switch, the circuit that you want to use is the one called split phase. Pretend that one of the windings shown is the two run windings properly connected and the other one is the start winding with the normally closed switch and the start capacitor just not shown. The motor on the drawing called Single Phase I never saw one like before.
 
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