Challenger Panel: Are there any issues with the breakers we are using?

Question

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

50 Amp x2 - AC units

40 Amp X1 - Oven

20 Amp x5

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

Type MH-T Circuit Breakers

20 | 20 Amp x5

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

Answer 1

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:

• GE THQL
• 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.

Answer 2

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.

Answer 3

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.

Answer 4

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.