Motor lacks power

[Majones1]

Maybe this will help??

http://waterheatertimer.org/How-to-wire ... tlets.html

Now that is a very informative page! Certainly one to bookmark. Thanks Dusty.

[JPG]

Bookmark?

I downloaded it!

[DLB]

Motor question! I have acquired a 1984 mark v with the Emerson 1 1/8 hp motor wired to 240v. The motor turns on and runs fine with no attachments installed on it (speed goes up and dow when speed dial is turned). I’ve tried attaching the band saw and belt sander and the motor will not turn them (motor turns on but just hums). I was able to turn both attachments Freely. The sheaves move freely and have been oiled, The belts are good and have good tension. I’ve pulled the motor removed the internal capacitor and had it checked (it’s fine). I inspected inside The motor and it appears to be clean and free of dust or any burn marks and turns freely with no grinding. I can stop the motor by hand with the 12” sanding disc installed and running at slowest speed. Just looking for Any suggestions to help resolve the issue before dumping $500.00 on a new motor. Thanks.

To this point there is a lot of good discussion about the shop wiring and the connection at the plug end of the power cord. I'm going to put those aside for now and presume you have 240 VAC to the black and white wires and ground to the green at the plug end of the cord. (NOT saying this is the case, just assuming it for now.) Based on that, you could have a bad motor, internal wiring error, electrical resistance, or mechanical resistance in the headstock.

Note that few of us have a 240 VAC headstock. Does the motor label indicate line frequency, likely either 50 Hz, 60 Hz, or 50/60 Hz? Does it indicate amperage? What are those values? Are we correct presuming you are on 60 Hz power? IIRC SS 240V headstocks are rated for either 50 or 60 Hz power, and users just convert speeds if they are on 50 Hz.

Do you have access to a multimeter? Does it include an AC Amps function? Is that clamp-on or in-line? Do you have a tachometer?

Mechanical resistance (unlikely) - With a typical SS headstock you should be able to turn the headstock by hand using either a drive hub or the knurled aluminum piece on the quill spindle. If this is very difficult or impossible to turn without something larger on the spindle this would point to a problem.

Testing the headstock electrically is going to depend on your access to a meter. Internally, the green wire from the power cord should go to the chassis, normally on the motor itself to a terminal specifically labeled for ground.

A local motor shop should be able to test/evaluate your motor. This is usually relatively inexpensive. Make sure you fully describe the problem. A motor operating at the correct voltage and current and producing correct RPM unloaded is almost always a good motor. (Unloaded RPM would be somewhat higher than the number on the label, maybe 3550+ in this case, which I'm assuming to be 3450 on the label for 60Hz power.

- David

[chapmanruss]

I suggest checking that both the new plug and the wall outlet are wired correctly.

[dusty]

Lack of "starting torgue" just might be the result of an open or leaky start capacitor.

I suggest you refrain from applying power until you have done some continuity tests and test the capacitor.

If doing this is not within your field of experience - go to a motor shop. It will be a lost less expensive than burning out the motor.

[edma194]

[quote=dusty post_id=290122 time=1635613747 user_id=1774
I suggest you refrain from applying power until you have done some continuity tests and test the capacitor.

If doing this is not within your field of experience - go to a motor shop. It will be a lot less expensive than burning out the motor.
[/quote]

Fully agreed. Applying power to this motor now could be damaging it. You really want a motor shop to check it out.

Can you see the motor nameplate and take a picture of it? Or at least get the model number, a lot of info should be available online just knowing that.

[JPG]

One thing to check - is the start circuit being disconnected after startup? Listen for click at both startup and wind down.