Page 1 of 2

Motor hums but wont turn - THANKS! Problem Solved!

Posted: Tue Jun 30, 2020 2:09 pm
by schnur07
One day I turned on the motor and it only hummed. I took the head stock off and removed the motor. The motor still hums disconnected from the pulley but it turns freely. It will also trip my surge protector if left on for a few seconds. This is a 1 1/8 hp motor.

I only have a volt-ohm meter and tried testing the capacitor. I hooked it up to ohms and it initially read low and gradually moved higher (on my analog one). So maybe the capacitor is ok from what I've read? That's as far as I know to go. Do I need to take it to a repair shop here in town? Is this an expensive repair?

thanks!

Re: Motor hums but wont turn

Posted: Tue Jun 30, 2020 3:54 pm
by garys
To start the motor, the centrifugal start switch needs to be working to put the capacitor inline for starting. Make sure the switch is moving freely and the contacts on it are clean and not burned.

Re: Motor hums but wont turn

Posted: Tue Jun 30, 2020 4:31 pm
by JPG
Crud has found a new home between the start switch contacts.

Rap the motor with a soft face hammer several times at different locations near the back end of the motor.

With any luck the crud will seek a new resting place.

1/2 second is more than long enough to see if it will run. Extended time with the power on and NOT running will quickly fry the run windings. Hopefully your circuit breaker has prevented that.

If starting on the bench secure it down. They like to jump around when starting untethered.

Re: Motor hums but wont turn

Posted: Tue Jun 30, 2020 6:20 pm
by schnur07
JPG wrote:Crud has found a new home between the start switch contacts.

Rap the motor with a soft face hammer several times at different locations near the back end of the motor..
So you're not referring to the toggle switch right? You're referring to some sort of contacts at the motor end? I blow around the motor with an air compressor. So if the start switch contacts aren't making contact does this mean the capacitor is not getting power?

thanks

Re: Motor hums but wont turn

Posted: Tue Jun 30, 2020 6:22 pm
by garys
If the start switch doesn't make contact, the start capacitor isn't switched into the motor circuit. The motor needs the capacitance of the capacitor to start running.

Re: Motor hums but wont turn

Posted: Tue Jun 30, 2020 6:34 pm
by schnur07
Thanks for the quick reply. Is there any way to get at where the start switch is and physically clean it or is internal to the motor housing?

Re: Motor hums but wont turn

Posted: Tue Jun 30, 2020 9:47 pm
by JPG
schnur07 wrote:Thanks for the quick reply. Is there any way to get at where the start switch is and physically clean it or is internal to the motor housing?
Very much so!

Try the soft faced hammer.

FWIW blowing can cause the crud to get in there.

Re: Motor hums but wont turn

Posted: Wed Jul 01, 2020 6:42 am
by br549
The start contacts are internal to the motor. There are different versions of the 1-1/8 hp motor, but here is what my GE start switch looks like. Fairly easy to get to after removing the end cap on the motor Just take your time and take pictures along the way if any doubt as to how it should go back together.

Here is a link to a thread about the GE start switch, and helpful advice I received from others.

https://www.shopsmith.com/ss_forum/main ... 17624.html

Re: Motor hums but wont turn

Posted: Wed Jul 01, 2020 11:44 am
by JPG
IF it is an Emerson motor, the contacts will be hidden under a mini 'dust' shield cup.

Re: Motor hums but wont turn

Posted: Thu Jul 02, 2020 4:26 pm
by schnur07
Mine is a GE motor. Don't know if there are different GE versions. V 115, RPM 3450, code H.