After reading this question and how much of uproar it caused. These are the breakers we are using with our challenger smb20(20-40)SN panel, apparently they are not all the same.

40 Amp x1 - Pool Panel

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50 Amp x2 - AC units

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40 Amp X1 - Oven

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20 Amp x5

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20 Amp x2 - Murray 20 Amp Tandem Single-Pole Type MH-T Circuit Breaker

Type MH-T Circuit Breakers

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20 | 20 Amp x5

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This was the best I could do without removing the breakers, which I'm not willing to due for the sake of my curiosity. I tried looking up issue numbers and didn't get any hits. I have no idea how to research these breakers. Any idea why we have so many different breakers? House is from the late 80s

Edit: Panel Diagram Image of Challenger Electrical Equipment Corp

SMB20(20-40)SN Mod 2,

SMB20(20-40)FN Mod 2

  • 5
    +10 for providing clear, focused, readable pics of all those breakers! Congrats!! I'm going to bookmark this and link to it as an example of how to do it for all those questions that we get without any pictures, or one, distant, fuzzy pic, or another that's such a close up we haven't a clue of what we're looking at. The only possible thing missing is a picture of the panel label, but you have, at least, provided the panel model number.
    – FreeMan
    Apr 29, 2022 at 11:22
  • Any chance of getting a picture of the inside diagram/label of the panel? Can't find any information on it. Maybe @ThreePhaseEel will chime in.
    – JACK
    Apr 29, 2022 at 12:09
  • 1
    @freeman if only you knew how many images I had to take before I got any kind of clear images. I thought I was in a photoshoot for playbay for a moment. Apr 29, 2022 at 17:22
  • Know that your efforts are appreciated!
    – FreeMan
    Apr 29, 2022 at 17:25
  • @JACK I searched for a couple hours looking for a better version of this diagram/label and couldn't find anything either. I've updated my question with a clickable image. It's in rough shape, but that's the best I can do. Apr 29, 2022 at 17:32

4 Answers 4


Eaton BR/C.

Your panel labeling indicates Challenger Type C breakers (or possibly Type A).

Those have been continuously made, by Challenger then Bryant then by Eaton's Cutler-Hammer brand. The key is, they are marketed as "BR type". But they are also marked type C.

And that is that.

What's wrong with bare Challenger Type C?

Nothing is wrong with the panel bus. However, Challenger cheated on their UL testing - their breakers do not work.

In the wake of that, BRyant acquired Challenger's bus design and continued it exactly as the Type BR. The "name change" from C to BR was to exclude defective "C" breakers from BR panels. However BR cross-listed their breakers type C, allowing them in Type C panels like yours. Clever!

What's wrong with MP type?

The Crouse-Hinds breakers are plainly labeled Type MP. That is one of the four major breaker types currently on the market:

  • Siemens MP (renamed to QP) (former Murray)
  • Square D HOM
  • Eaton BR/C (former Bryant and sold as Cutler-Hammer)

All of these types have similar form-factors, but different shapes of "bus stab". So they will roughly fit in each other's panels, but will not make reliable contact, and tend to suffer destructive arcing at the bus stab, because they are making corner contact instead of surface contact.

The Crouse-Hinds breakers are plainly labeled type MP, which we recognize to be a Murray/Siemens type, NOT compatible with BR/C buses.

Further evidence of that is next.

What about UL-Classified breakers?

UL has a procedure for brand X to certify a breaker for brand Y (competitor or obsolescent) panel. This category is called "UL-Classified" and are legal (satisfy NEC 110.2) when used as labeled.

In the 3/4" breaker lines, the only UL-Classified breakers on the market are Siemens QD and Eaton CHQ, both for Square D "QO" type panels.

In the 1" breaker lines, the only UL-Classified breakers are Eaton CL, which are Classified for a wide variety of older 1" panels including Murray and Crouse-Hinds.

So, Eaton's answer for Crouse-Hinds panels is their CL line, and not their BR line. Thus BR does not interchange with Crouse-Hinds.


Someone just whacked in what they had on the truck

This sort of alien invasion is a sign that someone, either the original installer or someone who was doing things in the panel, just grabbed whatever breakers they had on the truck that looked like they'd fit. This is bad because even though things may appear to fit, the breaker/busbar contact may not be correct, leading to arcing, burnups, and other such badness, especially during overcurrent conditions.

Since your panel is a Challenger, the correct replacements are Eaton BRs, which are cross-listed as Type C, and trivial to find. Note that you may wish to keep a bit of a close eye on your main breaker as well; Challenger type QFP breakers are based on a Zinsco design, and...are potentially not great as a result.

  • I guess the mickey mouse work involved, paid off, because we've only had 1 or 2 breaker go bad in 3 decades. Slow clap. I wouldn't know how to keep a close eye on our main breaker to be honest. Apr 30, 2022 at 5:34

So let's take these in order

  1. Crouse-Hinds - OK
  2. Challenger - Replace this
  3. Crouse-Hinds - OK
  4. Crouse-Hinds - OK
  5. Probably a Murray (Siemens) - OK
  6. Unknown (maybe a Siemens?) - If it doesn't say Challenger these are likely OK

Crouse-Hinds was eventually bought out by Eaton. Challenger was bought by Cutler-Hammer, which is also now owned by Eaton.

The key on Challenger is that Challenger had known defects. The cost of new compatible breakers isn't much, so it's worth replacing them. It might not be a bad idea to replace the other older breakers as well if you're going through the hassle, but there's no explicit safety issues there.

  • The funny thing is, those challengers are only on the AC units. We've actually never had workable AC units in this house until maybe 5 years ago and they only get used in the summer for a few months. Not exactly a very active breaker. Apr 29, 2022 at 17:35
  • Originally, my goal was to ask what to replace my breakers with to upgrade to AFCI breakers, since I think it probably makes more sense to just replace the breaker, than to figure out which outlet is the first in line and then replace that receptacle, Even though the outlet works and hardly gets used in the first place. And i've been reading the AFCI receptacles have issues themselves. But then I stumbled onto the challenger breaker drama.... Apr 29, 2022 at 17:38
  • So yea, after calling Eaton. They said the breaker I have was never recalled. It was the only Challenger GFCI breakers, which has a button in the front of it, my challenger breaker(s) are fine. Apr 29, 2022 at 18:17
  • This answer is not useful because it does not address whether the various breaker types are allowed in that specific panel. There are several that are acceptable in their corresponding panels but are a disaster waiting to happen in this panel. See the other answers for details.
    – nobody
    Apr 30, 2022 at 12:18

The NEC says:

110.3(B) Installation and Use. Equipment that is Listed, labeled, or both shall be installed and used in accordance with any instructions included in the listing or labeling.

Without seeing the exact label on your panel it would seem it is a series with a labelling that says to use Type C or Type A breakers, so the rest would seem to not meet this standard.

It becomes a bit tricky that many brands have been acquired by others, the Challenger brand is now owned by Eaton.

Reading of this document from Eaton breakers bearing the Eaton brand are compatible with the older Challenger (and Cutler-Hammer, Westinghouse and Bryant) branded panels. Eaton Type BR breakers normally bear the Type A or C marking also. BR's are usually a bit cheaper and more readily available.

There is a muddied clarity issue about using a second class of breakers labelled as "classified". Documents by Eaton which also makes these doesn't directly reference their own brands in their marketing documents so I would stick with the BR labelled breakers.

There was also a recall of some Challenger GFCI breakers, but the pictures don't seem to show those.

  • I've updated my question with a panel label/diagram. The breaker I know for a fact is the Murray MH-T. I have one in my hands. We replaced one maybe 5-6 years ago, It just slipped my mind. Does that help you figure out what kind of breaker I should replace these with? Apr 29, 2022 at 18:00
  • Called eaton, they claimed the breaker that I needed to replace mine with were BR type breakers. Yes, you're right, the GFCI breakers are the one had the recall. Not the breakers I have. Apr 29, 2022 at 18:32

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