My house came with a main panel that supports this type of circuit breaker.

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However, I am unable to find that type at the store and the breaker doesn't say what type it is. I thought it might be CH (as it's certainly thinner than BR) but it's not. Here are its comparisons with CH (on the right and below, respectively):

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Can you identify it so I know what to search for to get new ones?


I can see a SquareD logo on the side, and the red indicator window on the front makes it look like a Square D QO 20-Amp Single-Pole Circuit Breaker, model #QO120CP:

enter image description here enter image description here

The overall shape of the breaker and orientation of the contacts on the back seem to match your breaker.

  • Yes, I think that may be it. I'll have to go to a specialty electrical store, I hope they'll have them as the big box doesn't
    – amphibient
    Feb 2 '16 at 23:50
  • That's surprising as both the big blue and big orange big box stores near me have them in stock, one store is showing over 100 in stock, so they must be pretty common.
    – Johnny
    Feb 2 '16 at 23:53
  • 2
    Both QO and Homeline (which looks a lot like QO but is slightly different - check carefully, they do NOT interchange) are heavily stocked at both the blue and orange big boxes (and tiny hardware stores, too) around here. However, an electrical supply should also have them. Both are Square D products, and that logo is certainly obvious on your pictured breaker.
    – Ecnerwal
    Feb 3 '16 at 1:17
  • @amphibient Buy them on eBay, there are tons for around $4 for simple ones.
    – Ariel
    Feb 3 '16 at 10:28
  • Square D is a premium breaker, by premium I mean they are expensive. I love QO breakers you can usually instantly see the tripped breaker when you open the door. They also have a wide listing range I use them for residential and 3 phase.
    – Ed Beal
    Mar 8 '19 at 21:17

You have a Square-D Type QO (3/4" wide) breaker there. These are ridiculously common -- just about every big-box store and electrical supply house will have them, as well as industrial MRO suppliers and even small hardware stores.

The other possibilities can be ruled out as follows:

  • Eaton's CH fits a similar 3/4" form factor, but obviously would have different manufacturer nomenclature on it!
  • Square-D HOM (Homeline) breakers appear similar, but fit a 1" wide form factor, and often lack the red window on the front (Square-D calls the feature Visi-Trip™).
  • There are tons on eBay, quite a bit cheaper than a store. No reason to buy new, circuit breakers don't really go bad.
    – Ariel
    Feb 3 '16 at 10:27
  • 1
    @Ariel - But if your breaker does go bad, your house might burn down. I've been burned by counterfeit products on eBay more than once, and even if you get a genuine breaker, how do you know it hasn't been bouncing around the back of someone's truck for 3 years, or that it hasn't been taken out of a panel struck by lightning? It's not like they are exorbitantly expensive at a retailer, and you have more assurance that you're buying a genuine, unused product.
    – Johnny
    Feb 3 '16 at 18:25
  • 1
    @Ariel -- residential/light commercial miniature molded case breakers are generally rated to interrupt a single rated interrupting capacity fault. Heavier industrial units can be repaired/recalibrated, but there is no such facility on a miniature-type breaker. Feb 3 '16 at 23:19
  • @ThreePhaseEel Wait - you are saying they can handle a single short circuit and they are dead? I have a VERY hard time believing that. If that were the case why do they have a switch to turn them back on?
    – Ariel
    Feb 4 '16 at 2:44
  • I did some checking. They are rated to handle 2 shorts at full power. But full power shorts are very rare. Most shorts are arc shorts and the breaker can handle hundreds of those. Faulty breakers are also extremely rare in general if you check actual occurrences of fires.
    – Ariel
    Feb 4 '16 at 3:00

The first picture is a Square D Type QO This will not interchange with any other brand but Eaton and Siemens have classified clones that will fit. Stay with the Square D.

The second picture is a Cutler Hammer type CH (now called CHF). Excellent quality and no other brand will fit.

  • Hello, and welcome to Home Improvement. Thanks for the answer; keep 'em coming. And, you should probably take our tour so you'll know how best to contribute here. Dec 23 '19 at 22:34

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