A ground to neutral short should not stop the machine and may be how the breaker panel was wired. Single phase 240 volt power just has two hot lines and the neutral just center taps the transformer winding supplying the 240 volts. The twin breakers that supply this voltage, should both trip even if only one line has a short on it. Check the resistance of L1 and L2 lines to neutral that feed the motor with the breakers off. Each should read nearly equal resistance which usually is only a few ohms when correct. Make sure the motor turns freely by hand as a locked compressor can certainly pop the breakers. If the compressor appears locked, remove the cylinder head(s) and try to turn again. If still locked, one of the connecting rods may have broken in the crankcase. The other problem could be a broken valve assembly in a head. If the motor has a capacitor start and/or run capacitor, it can cause a breaker trip because the motor cannot start with a defective capacitor. Hope some of this helps!
Answers & Comments
A ground to neutral short should not stop the machine and may be how the breaker panel was wired. Single phase 240 volt power just has two hot lines and the neutral just center taps the transformer winding supplying the 240 volts. The twin breakers that supply this voltage, should both trip even if only one line has a short on it. Check the resistance of L1 and L2 lines to neutral that feed the motor with the breakers off. Each should read nearly equal resistance which usually is only a few ohms when correct. Make sure the motor turns freely by hand as a locked compressor can certainly pop the breakers. If the compressor appears locked, remove the cylinder head(s) and try to turn again. If still locked, one of the connecting rods may have broken in the crankcase. The other problem could be a broken valve assembly in a head. If the motor has a capacitor start and/or run capacitor, it can cause a breaker trip because the motor cannot start with a defective capacitor. Hope some of this helps!