Locked Up Compressor?

[gottawork]

I am wondering what would be the symptoms of only one of the two contactors failing (not energizing at all) on a part winding start 06E compressor. Would the motor try to start, pulling something less than LRA or pull full LRA?

[ej45]

The insulation on a compressor will melt at around 400 to 425*F and it takes about 5-10 seconds for the motor to reach that at lock rotor amps. Incremental start time delay relay between contactors should be around a half to one second. If that second relay fails to pull in the second contactor, one half the motor could burn.

You could disconnect the compressor and dry run the contactors to prove the operation.

[snipe70e]

If only one contact pulls in the windings will be over loaded and the overloads should open, hopefull before the windings burn out.

[duke of earl]

ej45,

I believe the time delay between contactors is more like 2-3 seconds since during the first second the motor windings are being charged and the motor is not yet in motion.

[hvaccolo]

ej45 is correct. only one second max between contactors. any more and your starters should trip (hopefully).