Any idea why some knucklehead would do this?
I believe it is a split bus and it suppose to be that way.
Isn’t this a Federal Pacific Panel? I would encourage look at previous post about FPE panels as well.
Roy, you’re right, I’ve never seen a Fed Pac. split bus before but they made em’! Ty!
What would have caused this?
Yep…
Looks like an arc flash probably caused it.
Damn! I got one correct! LOL! 
I agree that’s how it came form the factory. Somewhat obsolete nowadays.
Definitely a split buss panel. They fell under the 6 motions of the hand rule for a disconnect.
Jim is that why they designed it that way?
The 6 motions of the hand “rule”?
The cost of a large main breaker was expensive . The split bus allowed for smaller breakers to be used and keep the cost down.
Wow, so it’s all about cheaping out! :shock:
Ty!
This looks to me like there was a great deal of heat at the root of this problem, spread along about 2-3 inches of the wire that used to connect to that empty and scorched lug on the breaker. Surely the breaker would have to be malfunctioning in order for the wire to have gotten that hot, or could this result from using to small a conductor on that 20 amp breaker? I would worry too about damage to the insulation on the large conductor and the smaller one beneath. Time to call in an electrician, I would think.
Would do what?
