ECN Forum Forums Code Related Discussion Canadian Electrical Code Topics Thermal Overload Protection

Hi there dura,
What is this motor running, in terms of a load on the shaft?

Most single phase motors of this size often have a simple circuit-breaker on the terminal box of the motor, it is meant to trip at a given value of current, not unlike the over-current trip on a multi-plug board, if the motor does trip, you just press the overload and the motor should be able to be re-started.
I've never seen external overloads used on fractional HP motors, but I could be wrong too.

With larger motors, however, they normally have thermistors embedded in the windings, the tails of which come out into the motor terminal box and are connected to an external control circuit and contactor that disconnect the motor, should the windings get too hot.

In this case though, I don't think this application warrrants a thing like that.