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We are having our electrical service upgraded (from 100A to 200A) to support EV charging and to allow the installation of solar panels. As part of the upgrade the panel is also being relocated to the garage / workshop.

In doing this, should the contractor also be installing AFCI breakers on the existing circuits (which previously did not have AFCI protection)?

This is in Washington state.

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  • If it is not mandated in your locale, your choice, it is a good safety choice. It does empty the wallet a bit more. Not sure if insurance will give a better rate to make up for that. AFCI breakers are being called for in most new builds now.
    – crip659
    Apr 3, 2023 at 19:26
  • Do you have a electric dryer hooked up to 30 Amp circuit ?
    – Traveler
    Apr 3, 2023 at 19:48
  • @Ruskes - yes, but it's a 240V circuit, so no requirement for an AFCI there, no?
    – dlu
    Apr 3, 2023 at 19:51
  • The reason I was asking is, you can use the dryer plug to charge the EV while contemplating upgrading to 200 Amp. On Tesla it will give you 20 Miles per hour charging, 200 miles in 10 hours (overnight). No AFCI here
    – Traveler
    Apr 3, 2023 at 20:06
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    @crip659 I disagree, a service upgrade is a whole pile of cabbage to throw at very marginal safety benefits, given the options available to us by modern tech. A lot of smart people are working this problem, and these are not hard problems. Apr 3, 2023 at 21:21

2 Answers 2

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You may or may not actually need a heavy-up (service upgrade). In my area, if you do a panel replacement, requiring the utility to pull the meter, etc. then they normally force you to do a heavy-up if you were not already at the standard 200A. You may not actually need more power - my house could easily handle EV charging (if I had an EV) and stay well under 100A.

That being said, in my area at least the AFCI and other code requirements since the house was built don't get required simply because of a heavy-up. In addition to not having to put in any AFCI, the only GFCI added was for a receptacle next to the panel because the old receptacle had to be replaced in order to install the new panel properly, so that had to be GFCI and tamper resistant. I already have GFCI in most other required locations (bathrooms, kitchen) but no inspection was made or requirements added for other areas (e.g., laundry room, outside). My understanding is that this is typical, and it makes a lot of sense to me. If you require several hundred dollars (or more) of upgrades to bring everything up to modern code then many people might push off an already overdue panel replacement due to cost.

However, you have a possible complication:

As part of the upgrade the panel is also being relocated to the garage / workshop.

Depending on local practices, moving the panel to a different room might trigger requirements as if the circuits were brand new, which could include AFCI and GFCI and possibly even full inspection of the circuits to include tamper resistant receptacles and other relatively new requirements.

It is worth checking with either a long-time local electrician or with your local permitting office to find out what the normal practices are in your city/county/state. Better to find out in advance if AFCI (or other things) is needed.

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  • The panel upgrade is partly driven by wanting to support Level 2 EV charging -- not that we "need" that, but because it would be convenient & in the grand scheme of things not that expensive. For the most part, we do just fine on one Level 1 charger, 2 would be lovely. But there are times when the ability to get a full charge overnight at home would be very nice -- usually around holidays & visits from friends when we're using significant capacity each day. We could use a DC charger, but the cost is 5x home charging around here and the locations aren't great.
    – dlu
    Apr 5, 2023 at 15:22
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Wow, that's a lot of money for following "conventional wisdom". You're just very slightly early to attack this problem; a bunch of tech is starting to roll in to solve these problems - and they're not all costly like the SPAN panel.

Avoid conventional wisdom.

First, neither solar nor EVs require any service upgrade at all, except in one limited case for solar. EV designers knew perfectly well that making everyone get service upgrades was not feasible and would be a show-stopper for electric cars. So they provided a variety of solutions in the system design to make that unnecessary. It's not your father's battery charger.

Conventional wisdom #1: "My panel is 100A therefore my solar scamme-- I mean salesman informs me my solar would be limited to 20A without a service upgrade". No. Solar is an anti-load so it doesn't require any capacity at all! There are technical blips with smaller panels, but solar is desperately short of good people, and they get this wrong all the time. Actually, most "100A" panels have 125A internal busing, and as such can support 50A of solar with no additional hardware. It doesn't help that a lot of the solar industry is fairly scammy, and is mainly about up-selling you and financing. The actual solar hardware is laughably cheap.

Conventional wisdom #2: "Because EV charging was designed very stupidly, only 2 options exist: inadequate level 1, or huge level 2 at 50A, seven times the speed. There is no middle ground here." Obviously not, but why do people think that? Since the early days of EVs, they always tossed in a "Travel unit" intended for emergency use on the road (in 2014 the DC fast charge network wasn't so great). It accomodates many sockets. They "toss in" the normal one plus the RV-park plug. KOA Kampground in a pinch. It's an RV plug, not an EV plug, get it? But EVers wrongly latched onto it as "the official EV socket", which leads to so many wrong conclusions SMH... including "needs to be a plug/socket" when it doesn't.

Conventional wisdom #3: "My car HAS TO charge at 50A or it won't finish charging." You mean it won't finish by the end of dinner - most people have all night. Novice EVers tend to wildly overestimate the miles they drive, or wildly underestimate EV charging speed. If you are driving less than 2 hours a day, a 20A circuit will supply your needs. Technology Connections has a good video here on the subject but the numbers are low because Alec drives a crossover SUV and only charges 10 hours.

Conventional wisdom #4: "The EV will be an additional load on my panel". *Not at all. Load managment technolgy, which isn't even all that expensive, can dynamically change your EV's charging speed to make sure your service never overloads. This can allow 60A, even 80A charging on a 100A service. Not that you need that LOL.

Of course, electricians want to sell you the service upgrade because they make a ton of money when they do. That's absolutely the correct answer for their business; it's big money and very straightforward work, unlike dealing with the complexity of energy-management systems. As a stockholder of the electrician firm, I would want them to sell you a service upgrade and use any trick in the book to talk you into it.

Load-limit EV charging so it does not add to your panel's load.

Level 1/2 EV charging uses a neat trick they built into EV system design. That "charger thing" isn't - the charger is on the car, where it knows its own battery best. It listens to a signal from the "charger thing" which tells it how much power it can safely take from the house Right Now. Yes, it's dynamic - per SAE and IEC standards, the EV's onboard charger must listen to and obey this signal "on the fly".

So the EVSE (wall unit) can simply adjust this charge rate signal on the fly to correspond to the power headroom available in the service panel. Start your 5500W dryer, and watch your EV charge rate reduce by 5500W. It's really magic like that.

In the US, one of the most bargain-priced wall units (Emporia EVSE) with its Peak Demand Management feature, coupling with the Emporia Vue home energy monitor. In Europe is the Myenergi ZAPPI with its HARVI service wire sensor, using its "Grid Limit" feature.

By using these features, the EV is able to run at - no limit really; you're only capped at the "60A"/48A hard limit of the Emporia. That will satisfy even a hungry Hummer or RV.

Why does this work? Because of the secret. Your panel can deliver 24 kW, which is a lot. However, you rarely use it. Power companies and EPA say the average house averages about 1.2 kW -- meaning the average is 5% of the peak. A typical dryer, range, A/C or water heater pulls 5 kW, so clearly, they are short loads that don't run very long when they run. The rest of the time, the EV gets to run wide open. And if the EV is taking <12 kW, then it won't even be slowed down until 3 or more large appliances are running at once.

Either use your panel's headroom, or get a solar-ready meter pan.

Most "100A" panels actually have internal 125A bus rating (because they are also sold as 125A panels, or allow easy upgrade by swapping the main breaker). Those are able to run 50A of solar. That is calculated like this: The panel capacity for solar is deemed to be 120% of the bus rating. So that is 120A for a 100A bussed panel, and 150A for a 125A-bussed panel. The utility main + the solar breaker can't add up to more than that.

Note that the actual nameplate output of the solar inverter requires a breaker 125% that size. So a 50A solar breaker actually goes on a 40A (9600W) solar inverter.

However, if that is not enough, it is vastly cheaper to replace the "meter pan" (box outside that houses the mete) with a "Solar Ready" meter pan. The solar is fed on the utility side of the main breaker (often with its own breaker) and so, the solar has no limit other than your service limit. A 100A service can support 100A solar breaker.

Another option is to replace the meter pan with a modern "Meter-Main" that is solar ready. That has a main breaker onboard, which you then use to feed your old main panel. Again, the solar has no limits.

AFCI/GFCI aren't required for plain panel swaps

However depending on the scope of the other work, the AHJ may require it.

AFCI is good for detecting wiring faults in the walls, so people with older homes may want it.

Electric vehicle charging should never be on GFCI because that handy "charger thingie" (EVSE) already contains a smart GFCI, that will "self-reset" several times to try to get a charge to happen anyway. It won't do that if fed from a dumb GFCI, because the latter will also have tripped, leaving the EVSE stone dead and unable to even message you that charging failed. However in many NEC 2020 states, they did not repeal the fairly dumb requirement for GFCI on 240V sockets, so the plug/socket setup is a bad choice there. (well it's always a bad choice but nevermind that. People willing to spend a mint on a service upgrade shouldn't be chintzing out on putting up a socket so they can use the free travel unit... get a wall unit and hardwire it; avoiding the GFCI issue altogether Since they are GFCIs they will never need GFCI if hardwired.)

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