Please help with sizing electric motor circuit breaker

Thread Starter


Joined May 17, 2020
I just rewired the motor on my milling machine electric motor to run on 240v instead of 120v. and the circuit breaker needs a upgrade. (i'm not exactly sure if I should be referring to this as a thermal overload breaker or motor protection circuit breaker so I will just say circuit breaker)the breaker that was installed was 18A 125VAC. I have the power outlet setup as follows 240v line ran from 20 amp breaker at box to 20 amp receptacle in shop. 20 amp locking plug connected to motors power cord. the power cord runs to 240v 15 amp reversible power switch which connects to small electrical box on the outside of the motor that contains posts connecting the drum switch to the motor and also houses the circuit breaker. I would like to know what size the new breaker should be?Im guessing 15 amp 240v or 20 amp 240v? however not much room for guess work in electrical matters.there is I wiring diagram but it doesnt show the breaker im told it should be connected between either 1 and yellow or 4 and red. I appreciate any and all help thanks.20200516_220643.jpg20200516_223114.jpg20200516_223140.jpg20200516_223102.jpg20200510_032451.jpg20200510_032720.jpg


Joined May 17, 2020
A 10 Amp breaker will do ..
Hello. I am sorry to message you this way, but would it be possible to contact you privately (i do not see any messaging feature here). I need to ask something about an electronic ballast related thread you helped someone on here. I am short of time due to health issues. Email would be great. Thanks