1/2 hp Capacitor-start induction motor, reversible by manual switch, cap is good, centrifigul throw out is good. I believe the thermal overload may be bad.

Motor will hum but not start. If I start it by hand (in either direction) it will run till the centrifigul throw out kicks in then shuts down power. When the motor slows to about stop and the cetrifigul switches the other way the motor runs again. On, off, on, off.

The overlaod is a Klixon thermal with a manual reset. Connectors are P1, P2 and T1. P1 and P2 are the "contacts" while T1 is the thermal.

I have continuity on P2 and T1 but nothing on P1.

I am pretty sure the problem is in the overlaod switch but do not know how to test it for sure.

Dan

P1 is probably run winding, P2 is probably start winding, T1 is probably common (thru thermal switch). You said capacitor start, could it be a capacitor start/run? How many terminals on capacitor.

Check continiuty of run (P1) to ground. May be break in run winding.

P1 is probably run winding, P2 is probably start winding, T1 is probably common (thru thermal switch). You said capacitor start, could it be a capacitor start/run? How many terminals on capacitor.

Check continiuty of run (P1) to ground. May be break in run winding.

That is what I thought at first also but it is not the case. P1 and P2 are the contacts that should be "connecting" in the overload the way I see it and the T1 is the thermal control.

It is a true Capacitor-start induction motor.

What it seems to me is the run windings are not working due to the overload switch if that is possible. But I would think the overlaod would stop the start windings also.

Can I just jump P1 and P2 and see what happens? What could a quick flick of a switch hurt?

Shouldn't. If what I proposed is correct there should be a junper between Pi and P2. Have you checked for continuity between P1 and T1?

P1 woud go to start winding, P2 would go to start winding through centrifical switch. Common would return through therminal switch.

How many terminals on thermal? I'm guessing only 2, in and out.

If thermal switch is open motor frame should be hot to touch.