I am changing a 40A 2-pole (240V) Federal Pacific Electric Co. circuit breaker but I can't find one. Can I use a 50A 2-pole? It's for a wall oven.

  • What gauge of wire runs from the panel to the oven? Aug 8, 2015 at 0:33
  • Never increase the rating of a circuit breaker unless you have checked that all the wiring it serves, and the connections, can handle the higher load (which usually means replacing it all). Otherwise you're an electrical fire waiting to happen.
    – keshlam
    Aug 8, 2015 at 0:35

4 Answers 4



Your panel almost certainly is suffering from breaker-to-busbar contact damage, rendering it a ticking incendiary device.

See this answer for the gory details on just what is wrong with FPE's "breakers".

If you post a picture of your panel (dead front off), I can determine if you can have your electrician install one of the Eaton retrofit kits (the kit itself is several hundred $, but it saves significantly on labor as the existing enclosure can stay in place) or if you need a total panel replacement (cheaper parts, but more labor).

  • If the panel interior is big enough, Eaton makes a Cutler & Hammer retrofit kit that an electrician can install. Pull the meter, gut the old box of the bus bars and attachments, install the insert and rewire. And wow, now you can have GFCI and Arc Fault breakers as well. And you don't have to rip out the wall, insert a new panel, hope the wires and cables are long enough, etc. Aug 9, 2015 at 17:44
  • @FiascoLabs -- indeed; the main limit on deploying those is that some older panels don't have enough wire-bending space to fit a full-size retrofit kit, and tandem GFCI/AFCI breakers aren't a thing due to the electronics package taking up too much space. Aug 9, 2015 at 19:38
  • You can replace a 40A breaker with a 50A breaker, if your goal is to start an electrical fire....
    – VWFeature
    Jul 18, 2019 at 6:43

i am not an electrician but I do know federal pacific went out of business years ago after it was found that their boxes were responsible for a number of fires. Change the entire panel just to be safe. keeping the federal pacific panel is asking for a trouble.

  • 6
    This is good advice. When your breakers have a tendency to burn down houses, it becomes difficult to find them for sale anywhere.
    – Tester101
    Aug 8, 2015 at 1:00
  • 1
    Boy, I second that. And also the sentiment of the answer recommending not to install a 50A breaker on wire rated for 40A. But again, where these products were pulled off the market for starting fires I'd absolutely look into just replacing the panel, rather than replacing the 40A breaker even though you can find them if you look hard enough. Aug 8, 2015 at 2:06

Do not just install a 2 pole 50 amp Breaker. First your wire would need to be rated for the correct breaker. Second if the oven is rated at FLA (Full Load Amp) not to exceed 40 amps and there was a fault, the 50 amp breaker may not trip and could start a fire or kill someone. If you can wait look at Amazon, one quick search and there it was. Also look at a breaker broker they may have one, but be ready to put out was money, federal pacific are not cheap.

After reading your comment below, if your panel is now not allowing you to change out a breaker you have a bigger problem here. Your panel is starting to degrade and you need to call a electrician and get a quote to change the panel.

  • 1
    Thanks all, I ordered it on Amazon. I'm a first time circuit breaker changer & I did find a single 20 that somehow got stuck onto the double 40. Trying to install the 20 single resulted in my breaking it. The plastic groove fit well but the steel contact didn't want to go into the slot. What's the trick?
    – Rick Strom
    Aug 8, 2015 at 2:21
  • 8
    That's usually a good sign your Federal Pacific panel is in need of replacement. Somehow got stuck onto = overheated and plastic welded itself to the adjoining breaker. You're literally playing with fire here. Aug 8, 2015 at 5:14

Safety over current devices are uually easy to replace and most makes are interchangeable.mcbs are often clip on a rail and electrically connect,oddball makes are on the market,seek advice if in doubt or get an electrician to do this.Be safe be sure.Steve uk engineer.Do not fit a higher rated mcb,like for like only. Beside amp rating,the type is important.See other answers as well.pn,make sure it is an appoved mcb.

  • 1
    Most makes of circuit breaker are NOT interchangeable in general -- this is dangerous advice. And the FPE panel OP has is indeed one of the "oddballs", and has been responsible for more than a few fires in its history.
    – Nate S.
    Apr 29, 2019 at 18:47
  • 1
    Note that North American panelboard-style circuit breakers are a very different beast from the DIN-rail consumer unit enclosures used in IEC-based systems. The basic tradeoff is interchangeability/flexibility (DIN rail enclosures can mount just about anything you can think of) for density (I have a hard time imagining a consumer unit with 42 or 60 breakers in it that'd fit into a typical stud wall). And yes, FPE's non-breakers are a known fire hazard (they don't do their one job!). Apr 29, 2019 at 23:45
  • @NateStrickland In the UK, which Steve makes clear he is talking about, the MCB's are designed to be interchangeable... Makes life easy sorting replacements.
    – Solar Mike
    May 1, 2019 at 8:12
  • @SolarMike, that's fair, but I just wanted to be very clear that for the OP's question that this is trying to answer, the advice was incorrect and dangerous. If it's just a general comment about the compatibility of UK circuit breakers, then probably this question isn't the right place to post it.
    – Nate S.
    May 1, 2019 at 15:53

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.