Motor starts/runs appox 15 sec then trips breaker

by Larry
(Vestal, NY)

I have an Emerson compressor motor that starts and runs approx 15-20 seconds and then trips the breaker.

Here is what I know:

Model= mc302800av

120 vac
single phase
HP=SPL (don't know what this is)
RPM= 3450
FR=66
SF=1.0
Thermal Protected Auto

I replaced both capacitors
The breaker is 20 amp although not dedicated.
When I test the motor I unplug everything else on the circuit.
I am not using an extension cord.
I have removed the piston so just the motor is the load.
The motor states it is 15 FLA.
Is the inrush current too much?
Are the windings shorted?

__________________

Bill says...

Larry, I'm not an electric motor mechanic, yet I'm sure that if the motor is popping the breaker after 15 seconds and there is no load on the motor, then the motor itself is the problem.

Everything you've done to isolate the problem seems to have been done.

Take it to a motor rebuild shop. It may be the windings, I'm not sure.

Bill