Motor Repair - Single phase

Thread Starter


Joined Jun 24, 2017
What happens to a 110V single phase capacitor start motor when connected across 220V? Does the 125V start capacitor burn out before the motor windings do? We noticed that the motor windings were cold and test between windings gave us 2, 5 & 6 ohms. The motor only ran for 1 second before going off yet the windings didn't show any signs of overheating but the motor now won't start. Could it have burnt out the start capacitor or is the motor damaged? Any help will be appreciated


Joined Jul 18, 2013
If the start capacitor is underrated on 220vac then it could have failed.
If it has a start switch internal, then you could have blown the switch, there are are few possibilities.
The question is, why was it connected across 220v?


Joined Nov 6, 2012
You would have a very noticeable Hum/Buzz if the Motor tries to
start without a working Start-Capacitor, and Start-Winding, that is, if the other Windings are good.

You probably have a Circuit-Breaker that is over-rated for the Motor.
There are specially rated Circuit-Breakers designed specifically for Motor-Loads.

Some Motors may have a Thermally-Sensitive-Fuse embedded into the Windings,
it may, or may not be, "User-Serviceable", most likely not.

Since You can verify that You have Winding-Continuity,
look for other various connections that may have failed ..........

When You apply Power to the Motor, can You measure that Voltage inside the Motor ?

A Motor-Rewind/Repair-Shop may be your best bet if it's an internal problem.


Joined Jul 18, 2013
Your two windings, start and run are most likely the 5Ω & 2Ω in that order.
If the windings still have continuity it may be worth picking up a motor RUN RATED capacitor.
What is the HP of the motor?