All my panels in multiple California homes are square D QO, this makes it convenient to deal with electrical in any of them.

For an upcoming solar project I need to replace my main service meter combo panel. I will either need to use 200A service in a 225A (or more) rated busbar. Or I could use a 175A main breaker in a 200A rated bus bar.

I would prefer to use a 225A+ main service panel but QO doesn't offer one.

Are there other brands that I can use QO breakers in?

  • @Ecnerwal I need a combo meter panel. I added the detail to the main question
    – Matthew
    Commented Sep 18, 2022 at 19:24
  • 1
    yeah, you need to mention stuff like that lol. Commented Sep 18, 2022 at 20:24

2 Answers 2


You can't cross brands with any breaker

Yes, they seem to fit, and you think "Gosh, the companies got together and made breakers standardized" Well, they didn't. They were actually maneuvering to avoid each other's patents, and as a result every bus design is different, and the clips will not mate to the stabs properly - they'll make edge or corner contact and overheat.

So put that "swapping breaker brands" idea right out of your head. It is a dead letter.

With that said, I can tell you QO has a totally unique bus shape that will not interchange with anything else - not even close.

Now, there is one exception. UL has a way to certify one brand's breaker for a competitor's panel. This is called "UL-Classified". Note that manufacturers make a completely different line of breaker specifically for competitor panels. Their regular breakers are not cross-Classified for competitor panels, so an Eaton BR is not allowed in a Siemens panel, even though Eaton CL type is.

Eaton and Siemens both make UL-Classified breakers for QO panels, but unfortunately that does not solve your problem.

Square D does make 225A-bussed panels.

The key is don't confuse "main breaker" with "bus rating". Getting 70A of solar on a consumer panel needs exactly a >=225A bus rating but exactly a 200A main breaker. Unfortunately, QO's catalog numbers suffer from this very confusion.

  • QOxxx225Lyyy are convertible main-lug panels with 225A busing - exactly what it says on the tin for your purposes. You retrofit a QOM2 frame size main breaker and Bob's your uncle.
  • QOxxx200Myyy are main breaker panels. The "200" refers to the main breaker, and it is silent/ambiguous on the actual panel bus rating. Looking at model numbers only is futile. You will need to consult the labeling, spec sheet, QO dealer, or Square D itself.

Sidestep the problem with a "Solar-Ready" meter-main

Solar-Ready meter-mains have a neat trick. Above the main breaker, on the supply side, they either provide a direct tap or a second breaker.

By putting the solar power on the supply side of the main breaker, this entirely moots the 120% rule and you are free to run up to 200A of solar.

Noting that you are looking for a combo meter+main+all breakers (why??? they're awful) panel, those are sold in "Solar Ready" versions by someone or another. That goes far to explain why Square D will never make a combo panel with oversize busing, the only use for that is solar, and Solar Ready panels do a better job of filling that need.

Make your own Mega-Solar-Ready panel

A "Ranch Panel" is a variation on combo panel. It has meter + main + only 4-8 breaker spaces + thru lugs intended to go to a master panel elsewhere which will have all your breakers. "Elsewhere" can be 1 inch away.

In the 4-8 breaker spaces you install all your solar breakers - up to 200A of solar!

Off the "Thru Lugs" you go to a Regular Old main breaker panel with 200A busing. All your regular loads go there. Is the main breaker redundant? Not at all. It solves the 120% problem for both panels! This panel can't pull more than 200A obviously, but neither can the Ranch Panel. Crunch the numbers and see.

Since the Ranch Panel only serves solar, it doesn't really need to be QO type.

Abuse a 400A meter-main to same effect

With power company permission, install a 400A meter-main. These have two 200A breakers, with one being an optional add-on, allowing you to choose its size. The optional breaker you send to your solar. The other 200A breaker serves a Plain Old 200A main-lug panel where you put your normal loads. This panel can be anywhere, including 1" away from the meter-main.

They also make 400A ranch panels, which is simply a 200A ranch panel with an extra site for another optional 100-200A main breaker. This breaker could be used to feed the solar, or, you could flip the script and use the "mini-panel" for solar, and have the solo breaker feed a plain old main-lug panel for your loads. Just another way of doing the same thing.

Combo panels, generally, are anti-awesome

I would steer you away from a "combo panel". The problem is down the road. If you outgrow the panel or it becomes damaged or you run into obsolescence... now what? Your only option is a huge production: replace the whole thing, which requires the power company come and disconnect your service wires, permits, inspections, whole nine yards. With another costly $1000 combo panel, instead of simple cheap separates.

Whereas the more you have separates, the more liberty you have to simply change out the one thing that is not working for you. Classically, people would run out of "breaker spaces", and that's particularly acute with all-in-ones, which give shamefully few breaker spaces to limit vertical size. Many are advertised as "16/32" meaning 16 spaces 32 circuits, but guess what - that "32 circuit" number is malarkey, since most circuits need full-size breakers now. Also, we're expecting a "smart grid" in the next 10 years - panels like Span are already doing it, and we expect that to retrofittable into existing panels. But the tech may not physically fit in QO's smaller package size.

All that to say, I'd rather see you get a meter or meter-main, and a plain old 40-space master panel for your breakers, than try to reduce box count by 1 with an all-in-one.

Remember your solar needs to have Rapid Disconnect in any case, and with microinverters, any of my suggestions above will handle that for you without an additional box.

  • Great answer. Thanks. My setup is a little different. I actually have a 200A main panel with 12 spaces. This feeds a subpanel, and that subpanel is actually where the solar will connect. Thus it's ok to have a small number of spaces in the main service panel
    – Matthew
    Commented Sep 18, 2022 at 22:55
  • 2
    @Matthew Yeah, this is a fantastic example of an XY problem. And let me assure you, this situation definitely deserves a more complete examination! Perhaps you can compose a new question, giving us all the details of your solar config, so we help you interpret the 120% rule and figure out how to get the most performance for the least money. Having to replace a combo-main sounds heinous; maybe we can sidestep that altogether. Commented Sep 18, 2022 at 23:29
  • Nonetheless I learned that you can't just swap brands even though they fit. I knew about UL listing, but I didn't realize that was separate. Plus I learned that QO aren't listed for use in any other panel types (I think) it's only a little bit of an XY problem, I didn't want to ask about a holistic solar design (yet)
    – Matthew
    Commented Sep 18, 2022 at 23:31
  • @Matthew correct, but if you want to ask about your panel configuration and how to max out the available solar, we may be able to get you the capacity you need quite inexpensively. It's up to you. Commented Sep 18, 2022 at 23:32

Following new info that this needs to be a meter/main, it appears that 400A meter mains are your only QO option above 200A, so, there are 17 results, I chose the second page to show, they are all kinda spendy.

More search results from Schneider Electric

(Prior to "needs to be a meter/main") False premises, as far as I can see. I see two 3 phase panels and three single phase panels when I limit search results to QO, Main Breaker, 225A at Schneider's web site. The prices are full list price circa 2022, of course. You might do better in practice. No affiliation other than I have a pair of QO panels myself (boring old 200A units.)

There are cross-listed breakers for QO panels from other makers, I'm not aware of any other maker for the panels, but I might learn something new-to-me if someone knows otherwise.

Search results from Schneider electric

  • I need a meter combo. Sorry for missing that detail!
    – Matthew
    Commented Sep 18, 2022 at 19:30
  • 1
    Then you get to buy a 400A unit to stay with QO, since 225 seems to be discontinued - or you get something else that only supplies your QO subpanels inside. Or you leave the "one breaker type to rule them all" bus entirely.
    – Ecnerwal
    Commented Sep 18, 2022 at 19:38
  • Well, for similar price to the 400A units there's this thing with a 225A bus, that didn't come up in the standard seach: QOWC60M200PFY Square DTM Energy Center
    – Ecnerwal
    Commented Sep 18, 2022 at 20:00
  • 2
    FYI the se.com prices are not always unit prices. They are wholesale prices, sometimes for an entire case/pallet of the product in question. For example, QO142M200PCVP is “$1581” at SE - for a pallet of 18. One will run you $350 from HD at retail. You have to dig through the details to see which it is. Some of the prices might not be as bad as they look.
    – nobody
    Commented Sep 18, 2022 at 21:21
  • 1
    Yeah, se.com online prices are wildly imaginary figures, a bit like airline card rates or hospital list prices. This is one of the many problems with shopping "online" for electrical gear. Commented Sep 19, 2022 at 0:01

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