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Strange smoking after Capicitor change

Posted: Thu Aug 10, 2017 7:03 pm
by davetheman81
I purchased a nice mark V last week with the 1 1/8 HP motor. It worked fine for a day and then i went away on business. When i came back i turned it on and the motor trued to go in reverse and then spin slowly forward, so i replaced the cap with a model of the same specs from grainger.


I turned it back on and it ran at nornal speed but started billowing white smoke after 30 seconds and the motor was loud..... what did i do? I also noticed some of the wax strings on the windings are broken

thanks - dave

Re: Strange smoking after Capicitor change

Posted: Thu Aug 10, 2017 10:00 pm
by BuckeyeDennis
davetheman81 wrote:I purchased a nice mark V last week with the 1 1/8 HP motor. It worked fine for a day and then i went away on business. When i came back i turned it on and the motor trued to go in reverse and then spin slowly forward, so i replaced the cap with a model of the same specs from grainger.


I turned it back on and it ran at nornal speed but started billowing white smoke after 30 seconds and the motor was loud..... what did i do? I also noticed some of the wax strings on the windings are broken

thanks - dave
I'll venture a guess, but JPG is the motor guru, so you'll want to see what he thinks.

Your initial symptom does sound like a start-circuit problem. But the start relay is more likely to fail than the capacitor. So my guess is that you replaced the wrong device. Then the start relay failed to open after that fatal spinup, and cooked the start windings. :(

Re: Strange smoking after Capicitor change

Posted: Fri Aug 11, 2017 4:23 pm
by JPG
Sadly I must agree!(Without further details.)

It MAY be salvageable if the start windings are not shorted.

Re: Strange smoking after Capicitor change

Posted: Fri Aug 11, 2017 5:04 pm
by Hobbyman2
How did you determine the capacitor was bad?


https://www.youtube.com/watch?v=FZrvrwKlH94

Re: Strange smoking after Capicitor change

Posted: Fri Aug 11, 2017 6:10 pm
by JPG
Hobbyman2 wrote:How did you determine the capacitor was bad?


https://www.youtube.com/watch?v=FZrvrwKlH94
The question was "how did davetheman81 determine the capacitor was bad".

Re: Strange smoking after Capicitor change

Posted: Fri Aug 11, 2017 6:18 pm
by Hobbyman2
that was what I was wondering.