Compressor stalls on re-start. Capacitor versus unloader valve

by Bruce

Compressor would run fine until restart against low pressure set point (~40 psi). Checked the unloader valve and it was fine (could hear it PSSSSSST at high set shut off).

Swapped out the start up capacitor (on top of the motor), using a great deal of care (stored voltage, you know). Found a very close MFD rated one on another piece of equipment's motor and it worked perfectly. Now that I know what the problem was, I'll get the exact capacitor and all will be well with both motors.