I went to a call with a shorted comp one day. I must have been in a mood because I actually reset the breaker a few times to watch the amp draw as it snapped the breaker silly.

On the 3rd try it tripped. So I then took apart the unit to do a meg ohm test, etc. Comp shorted directly to ground. Then I noticed no more power to anything when I saw the contactor not closed anymore. The whole house was dead.

Went to the main panel expecting the main 200 AMP to be tripped (which has happened before) and nope, it wasn't.

Shortly comes a APS service truck out to the neighborhood. He opened the transformer box and I blew a 15 amp fuse on the primary side of the transformer (12,000 volts)!

I killed the power to 4 houses!