Federal Pacific Electric Company (FPE) was one a common manufacturers of breaker boxes up until the 1980
FPE Breaker Boxes were discontinued after a a class action lawsuit.
The problem with Federal Pacific is the breakers. They may or may not trip when they are suppose to.
Example : a GE or Square D 20amp breaker will probably trip around 21 amps, or so, but a federal pacific 20 amp breaker would probably trip around 24 or 25 amps, or it might not trip at all, especially if it is old.
I ve had experiences with federal pacific breakers that would not trip at all.
I had one customer who called because the walls where a plug was was hot to the touch. (not the outlet but 2 feet above the outlet). Sure enough when I arrived it was smoking hot.
After checking I found that the actual wiring coming down the wall to the outlet was generating the heat.
It was early January and cold, so I asked were they using space heaters, and they were. It appeared they had 2 heaters that pulled 15amps each, plugged up in the same plug.
The wire size was 15 amps, on a 15amp Federal Pacific Breaker.
The breaker did not trip at 15 amps as it was supposed to. It allowed the customer to plug in and use (2) 15amp heaters at the same time. Thus 30amps being fed on a 15amp wiring.