Just an interesting story i thought i would share about an air conditioner i encountered yesterday. Customer says the unit trips breaker and she leads me to disconnect ( breaker style), which is tripped. She resets breaker and i hear the compressor begin to slam like a motor that is running into something during revolution and then the breaker trips. I pull the electrical cover panel off the condenser and find the capacitor missing! An 80 mfd capacitor is missing and the loose wires from the contactor and start winding are touching the casing to the unit! Anyways, i install new capacitor and flip breaker to get the same reult. I began to check things to ground but nothing is grounded. Puzzeled, my fellow technician flips the breaker once more. I here the revolution sound once and then it gets quite. Fan is running and i begin to here a slapping sound. I realize quickly that the sound is coming from the metal conduit. The wires were slapping arounf inside the conduit like a water hose with too mush water! I stick my insulated screw driver to the conduit and it sticks with magnitism! All of this happening within about seven seconds i began to reach for the breaker when BOOOOOMM!!!!!! The compressor leads blow out on this 410A scroll commpressor and black gas smothers and blinds the working space.
The loose wires in the cabinet are probable cause for the windings, which i now assume were internally shorted together, to short out. The short caused an extreme overcurent of electricity and the overload blew out the terminals.
You can bet ill be looking deeper into these situations before resetting any breakers from now on. Things could have gotten ugly.