Need help diagnosing motor problem

[Matt Day]

I have a mid 80's Delta 33-890 RAS that I restored - tear down, clean/prime/paint, reassembly. I ran the motor at the PO's house and it worked fine on 110, but I need to run it on 220. So I double, triple, and quadruple checked the wiring and I'm confident that it is correct. Problem is the motor is not running correctly.

When I turned it on for the first time on 220, it turned on right away and spun up but it was loud, louder than a motor without a blade should be. As I was checking it out, I saw a spark at the motor protector. I turned it off immediately and checked for damage, saw none other than a touch of black, then rechecked all the wiring. Next time I tried it, it ran loudly for about 20 seconds before I saw/smelled smoke from the fan/winding area. I immediately shut it down again and have not tried it again since. I hope I didn't let all the magic smoke out! I did notice the capacitor was warm for quite a while after I turned it off an unplugged it - like 20 minutes later.

So I did some research on the forum and dug into the motor, thinking it was the centrifugal switch, capacitor, or too much dust. I should mention that when I mounted the motor to the yoke a decent amount of dust dislodged from inside the motor housing and came out - hopefully the smoke had something to do with that, though it smelled more electrical than wood smoke.

I took the housing apart and the bearings aren't seized or anything but they aren't in great shape so I'll replace them. I cleaned what I thought was the centrifugal switch (round parts on the non blade side, shown at right of first picture), but is that what it is?

The windings look find, no signs of burning anywhere but I gave them a thorough cleaning with compressed air.

So couple questions:

1) Should I replace the start capacitor? Does it matter that it's labeled 115V and I'm running it on 220V? I thought that the transformer in the starter box would take care of that, but maybe not.
2) Replace the motor protector?

Any thoughts or suggestions?

[Jesse Busenitz]

It sounds like your capacitor is staying engaged which is not good! DAMHIKT..... Have you tested the capacitor?

[David L Morse]

Ok, here are the known facts:

1) When originally wired for 110 the motor worked perfectly.

2) After rewiring for 220 the motor no longer worked properly.

It is certainly possible that a component (capacitor, centrifugal switch, overload protection etc.) chose that exact moment to fail. I think it is more likely that something is wrong with the 220 wiring even after your fourth check, and that is the first thing I would test. Take the motor back to the 110 configuration and see what happens.

[Rick Potter]

Sorry if this is a silly question, but are you sure this is a dual voltage motor?? Could it be a replacement motor?

[Cary Falk]

Sorry if this is a silly question, but are you sure this is a dual voltage motor?? Could it be a replacement motor?

This is my first thought as well. I also agree you should change it back to 110V and see if it still runs.

[Rod Sheridan]

Hi Matt, that round item looks like a blade brake to me.

The square black object to the right of the capacitor looks like a current sensing relay to drop out the start winding. I have seen those where they are orientation sensitive, mount them the wrong way and they don't work.

Regards, Rod.

[Rick Lizek]

So couple questions:

1) Should I replace the start capacitor? Does it matter that it's labeled 115V and I'm running it on 220V? I thought that the transformer in the starter box would take care of that, but maybe not.
2) Replace the motor protector?

Any thoughts or suggestions?[/QUOTE]
If it's not labeled dual voltage, it's not a dual voltage motor. Take a picture of the label. If it's dual voltage you have to switch some wires around. You may have fried the motor.

[Matt Day]

Here's a pic of the motor cover - it's dual voltage for sure. I also included a wiring diagram for the motor. This model also has a giant starter box that includes the transformer, attached is a pic of that diagram too.

[Matt Day]

Rod, I had a feeling that was the brake, and if I checked the wiring diagram I would have seen that! After all the things I read it's a dead ringer for a CF. Thanks. I checked the sensor wiring, and all other wiring and it all looks correct. And that sensor is also what tells the capacitor to turn off as well as the start winding? Could that be broken? Any way to test?

My next steps will be to replace the bearings (I took them off already), test the capacitor (after I google that), then wire for 110 and see what happens.

Anything else?

[Rod Sheridan]

Rod, I had a feeling that was the brake, and if I checked the wiring diagram I would have seen that! After all the things I read it's a dead ringer for a CF. Thanks. I checked the sensor wiring, and all other wiring and it all looks correct. And that sensor is also what tells the capacitor to turn off as well as the start winding? Could that be broken? Any way to test?

My next steps will be to replace the bearings (I took them off already), test the capacitor (after I google that), then wire for 110 and see what happens.

Anything else?

Hi, you can check that the current sensing relay turns off by measuring the current in the capacitor with a clamp on ammeter. The current should be zero once the motor starts.

Regards, Rod.

P.S. Make sure the motor is in the same orientation as originally installed, those relays can be position sensitive.

[John McClanahan]

Hi Matt, that round item looks like a blade brake to me.

The square black object to the right of the capacitor looks like a current sensing relay to drop out the start winding. I have seen those where they are orientation sensitive, mount them the wrong way and they don't work.

Regards, Rod.

+1.
If it were me, at this point I would have someone else check the wiring colors at the motor, just in case I was repeating a mistake.


John

[Matt Day]

Thanks so far everyone. I hit a couple bumps in the road today.

First was that the bearings I picked up, though labeled the same (6203) were different than the ones I was replacing. Turns out there's different bore diameter, and I have the non standard one on the RAS. So I need to order some 5/8" ID bearings, instead of the standard 17mm. Silly American bearings!

Second is I can't get my digital multimeter to test the capacitor. It is capable of doing so by design, but it keeps giving me an error message.

QUESTION: Could anyone tell me based on the wiring diagrams if the cap should be 220 instead of 110? I don't know if maybe the cap only sees 110 somehow or if it should be replaced with a 220.

[David L Morse]

If wired according to the schematic and no shorts in the main windings the capacitor, start winding and brake will see only 120V.

[Matt Day]

Thanks for the quick reply David! The replacement is $6 from Mcmaster, so I'm just going to replace it.

[Ronald Blue]

6203 bearings have always been metric series bearings. Are you sure you didn't misread it? An inch series bearing with a .625 bore and 1.375 outside diameter is a 1623ZZ in one brand. If the number is hard to read which it often is on old bearings it would be easy to make that mistake. Good luck.