I just bought a house that has a Challenger load center (circuit breaker panel).

I learned from this answer and others here that Challenger circuit breakers are fire hazards and all of the breakers in the panel should be replaced with BR-type breakers.

My question is, does this include the 200 Amp main breaker (Type QFP2T)? And if so, what would be a valid replacement for it?

Challenger Panel

  • 7
    If you're going to replace all the breakers, this is a great opportunity to replace the box and gain a me space for future expansion. Maybe even to go up to higher amperage service. Or even to plan for a subpanel with transfer switch or transfer linkage to allow running essentials like heating and refrigeration from a generator or stored power at some point. The one downside of replacing the box is that code may not require you to install the meter and master breaker in a box outside the house, which would be another cost increment. But you'll never have a better opportunity!
    – keshlam
    Aug 16, 2023 at 7:16

2 Answers 2


You're kinda stuck

The issue with the style of panel you have is that the main breaker, instead of being bolted to the busbars the way modern main breakers are mounted, is plugged onto the bussing system. However, instead of using the same bus stab system as the rest of the panel, Challenger used a stub of Zinsco-style bus to mount some of their 200A mains, probably because that was the 200A breaker design they could get rights to.

As a result of this, there just aren't good replacements available short of wholesale panel replacement or gutting the panel and fitting a BR main breaker retrofit interior, especially given that your existing main breaker has a staggered side-exit lug configuration. (As an aside, Milbank still makes 200A Zinsco-style main breakers, but not in the side-exit configuration that you have.)

I would simply keep a close eye on the breaker for any symptoms of trouble (overheating or malfunction) for now: the Zinsco bus system was not a good performer at the end of the day, but I'm not aware of any way to retrofit say an Eaton BW main breaker to these panels.


Such product expertise. Bless ThreePhaseEel!

However there is one other way to secure a reliable main breaker: replace the meter pan with a meter-main. This is a meter pan with a built-in main breaker.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.