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Motor hums but doesn't turn
Posted: Mon Jun 13, 2022 2:25 pm
by frozen
When I turn the switch on the motor hums but does not turn. I am guessing maybe it is the starter capacitor (from another post)
If not what? and if if it is the capacitor how do I fix it?
Thanks!
Al
Re: Motor hums but doesn't turn
Posted: Mon Jun 13, 2022 3:23 pm
by jsburger
Start capacitors rarely go bad. It is more likely the contacts of the start switch are dirty and not making contact. Try blowing the sawdust out of the motor and see if that fixes it.
Re: Motor hums but doesn't turn
Posted: Mon Jun 13, 2022 3:44 pm
by dusty
When you turn it on/off you should hear a distinct click. This is the start relay when it is energized.
Be aware that you can do serious damage to the motor if it hums too often or for too long.
Re: Motor hums but doesn't turn
Posted: Mon Jun 13, 2022 5:44 pm
by frozen
Thanks jsburger and dusty, I removed the motor and reversed the vacuum into it thoroughly and it did the job.
Much appreciated!
Re: Motor hums but doesn't turn
Posted: Tue Jun 14, 2022 12:11 am
by JPG
Mark V do not have a start relay, only a mechanical centrifugally operated switch.
Re: Motor hums but doesn't turn
Posted: Wed Jun 15, 2022 8:44 pm
by frozen
I spoke a bit soon.... I used it for a while and then it did it again. I am wondering if it would be advisable to put some sort of air filter around the vent holes on it to keep the dust out? Any thoughts?
Re: Motor hums but doesn't turn
Posted: Wed Jun 15, 2022 9:45 pm
by jsburger
frozen wrote: Wed Jun 15, 2022 8:44 pm
I spoke a bit soon.... I used it for a while and then it did it again. I am wondering if it would be advisable to put some sort of air filter around the vent holes on it to keep the dust out? Any thoughts?
No. The centrifugal switch contacts are probably dirty and need more cleaning than just blowing the dust out.
Re: Motor hums but doesn't turn
Posted: Thu Jun 16, 2022 9:14 pm
by Hobbyman2
A lot of folks replace the capacitor and it wasnt the issue ,
https://www.youtube.com/watch?v=AYHuJuMPy_A , they ,,can,, go bad but testing them first is a good idea , it can save time putting the thing back together just to take it apart again .
Re: Motor hums but doesn't turn
Posted: Fri Jun 17, 2022 12:36 am
by frozen
Thanks JPG and jsburger,
Is it difficult to disassemble it to clean the contacts? Is there a 'how to' on it?
If not do I simply replace the switch?
Thanks!
Re: Motor hums but doesn't turn
Posted: Fri Jun 17, 2022 8:26 am
by JPG
Assuming it is an emerson motor, the contacts are somewhat obscured. Replacement parts source is all but non-existant.
Bill Mayo (RIP) recommended soft blows with a soft face hammer to try to dislodge any crud. Tap at different locations and try to start.(not too often in too short a time span)