Does this electric panel replacement plan make sense?

Question

I am pretty sure I need to replace my electric service and panel. What I have is 200A and Siemens 40 space panel setup when this 1200sqft. house was built in early 60s northeast USA. The elbow where like meets house is sideways, the service cable coming into the house has a lot of alligatoring, and the meter box outside is so rusted that the utility co said they won't open as if they do it probably won't close. I've had 3 electricians look in the panel and all identified the same key issues.

• corrosion on bus bars and behind breakers, as first noted in this question: Is this corrosion in my electrical panel, and is it a safety issue?

• many alien breakers are on the panel

• the panel has no open spaces

I have 4 new circuits to add, and within the next 5 years I anticipate needing another 2 spaces for an electric car charger, maybe 2 more for more mini-splits though that might replace existing circuits. The house was setup to be all electric in the 60s, so most of what you could imagine needing circuits for is already filling up these 40 slots (e.g. 4 old 240A baseboard circuits taking 8 spaces, a mini-split, well pump, dryer, range and kitchen appliances, chest freezer, subpanel in barn, etc.)

Faced with a need for 4 to 8 more spaces than I have, over the next 5 years, along with the panel itself expected to fail within 10 years if no action taken, it seems worth upgrading the panel. I got 3 proposals to do so and I think option A makes sense (also my preferred electrician), but before making this 50+yr decision I wanted to ask this broader community if this option makes sense.

A. Preferred electrician gave quote for subpanel to cover new needed circuits, and quote to just replace service and panel. Subpanel requires moving some existing circuits, and ultimately that was just a few hundred cheaper than replacing the whole service and panel. They insist on using SquareD Q0 200A 54 space panel, they say it's all they use because they never have problems with it. I persisted in asking for the Homeline 40/80 and they're very reluctant but seem willing if I insist. For the whole upgrade, using the SquareD Q0 54 space panel, they quoted apx. $3200, including replacing all those breakers, 2 new grounds, new meter box outside, new service line. Seems like a good deal, I think they value my returning business, but they do lots of commercial/industrial with residential as side team. I asked about permits, they said no need since it's a repair, suggested against it but would leave it to me if I want to go that route.

B. GC electrician who's done some handy quick fixes said they could do this job too. He insisted that tandem breakers are the way to go, and that I could just go that route and buy time on the main panel. He insisted on using Homeline 40/80, emphasized how 80 circuits is much more than 54. Said he'd do the job for same or cheaper than that other quote, even before I told him what it was, which did not give me confidence in him. I also asked this guy about permits, he said it's a bad idea to get township inspectors involved as they'll inspect the whole home, document everything, raise taxes and make future work require permits.

C. Third electrician, new to me but well rated and in business for decades. Very focused on code compliance, insisted they'd get a permit with their own 3rd party inspector. Said Homeline 40/80 makes the most sense, the Q0 panel is huge and no one has a 54 space panel. He asked about other quotes and said back of the envelope he'd need at least $5,000 to do it. When he heard the first quote, he said "do that, take the Q0 panel, before they change their mind!"

So, I think I'll go with the first option. Q0 being unusually large and having a unique connector system made me wary of it. But top notch electrical safety feels like a worthwhile investment. Even more so since the house was built DIY'd and I'd like to bolster safety as much as I can, e.g. getting all breakers compatible and high quality, putting a few wacky circuits on AFCI, etc.

Is option A (the Q0 54 space panel) reasonable for a residential, fully electric home, or is a 54 space Q0 panel excessive or otherwise problematic? On the other hand, is relying so heavily on tandem breakers reasonable with options B or C using a 40/80 space panel?

I understand pricing is out of bounds, it's more if option A is a sensible approach. In any case I will be replacing the panel. It comes down to Q0 54 space, or Homeline 40/80 relying heavily on tandem breakers.

Answer 1

Tandems don't stretch as far as you are imagining. Several types of breakers just don't come in tandem format. For example high draw and 240 V will typically take up 2 full spaces, AFCI and GFCI also don't tend to do wall as tandems.

SquareD does have tandem breakers and a quick search tells me you can put up to 10 tandems in their 54 space box. That brings you up to 64 circuits of which 44 will need to be full size. Chances are that's going to turn out just as well as whatever mix you will end up putting in the 40/80 homeline.

Check which breakers are not available in tandem format for homeline and then count how many spaces those will take up in your installation, if that exceeds 16 then you are better of with more actual spaces. I'm already counting 16 if the 4 baseboard heaters, range, dryer, minisplit and barn subpanel all need full size breakers of the 240V variety.

Answer 2

The 00s called and want their "Just use tandems" advice back.

In 2014 NEC greatly increased the number of GFCIs and AFCIs you need in residential panels. 2017, 2020 and 2023 editions increased them further. So you're not going to go very far with tandems unless you ring the panel with 4-11/16" junction boxes to stick AFCI/GFCI deadfronts 2 at a time in them.

Square D HOMeline is the cheapest panel on the market, that's why it's the darling of the money-chasing electricians. Square D QO is the most overpriced, having 90% of the quality of Eaton CH at 130% of the cost. I'm surprised to see the most lowball electrician spec it, but okay.

Q0 being unusually large and having a unique connector system made me wary of it.

Wait, WHAT??? No, the various brands' 1" breakers are NOT interchangeable. They burn up bus stabs when they are interchanged. From your older pix you already had a dog's breakfast (breakerfest?) with BRyant breakers in amongst the QP's.

To be compatible with a competitor panel, the breaker must be certified (UL-Classified) for those panels, and the only one for 1" panels is Eaton CL.

However QO has the most diversity of UL-Classified breakers, including Siemens QD and Eaton CHQ, both made explicitly for Square D QO and no other panel. That's what happens when you overprice your breakers LOL.

However, both QO and Eaton CH have the weakness that due to their smaller breaker package, more exotic things are simply not made. The only tandems are 15/20 and 20/20, with no quadplex at all. AFCIs are limited, no 2-pole AFCIs. And the UL-Classified types are no help here. That may be a bigger concern to you.