Electrical safety circuit breakers

A lot of you, if not all of you, have heard about breakers that have issues tripping off in a fault or overload condition. Federal Pacific otherwise known as FPE and Zinsco breakers are great (I mean bad) examples. you’ve also heard about people putting pennies in an old fuse panel. All of these examples could give you this outcome.

I have seen many old BX or AC cables that the wire insulation has crystallized because of the many times the wire was heated (overloaded) and cooled. The old insulation is not what insulation is today. If you move these cables around you end up, breaking up that insulation and can create a short circuit. Water can and will exacerbate the situation.

Can you imagine if this was inside of your wall? And to be clear, this would be inside of a wall of a home from the 20s 30s or 40s. Dry Piny studs and wood lath.