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As part of some recent (fall 2022) licensed and inspected electrical work I was having done anyway, I also had a NEMA 14-50 receptacle (with code-compliant 50A GFCI breaker in the subpanel) installed in my garage. The local power company is offering very generous subsidies for people who make their house “EV-ready.” However, many of the answers on this site have gone into the benefits of hard-wiring EVSE rather than using a plug. So, how would I change this in-wall receptacle to a hard-wire connection? Is it as simple as replacing the face plate and receptacle with a box, and replacing the GFCI breaker with a plain one?

NEMA 14-50 receptacle installed inside the wall

I know this is very similar to Installing hardwire EVSE from existing NEMA 14-50?, but my question is slightly different as mine is already installed inside drywall.

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    The reason to hardwire instead of a plug, is that quite a few places require garage outlet to have GFCI protection. No GFCI outlets that size yet and the GFCI breakers are quite expensive at that size. If that outlet was done to local code and inspected then it is good. Most code grandfathers in circuit done before, if they were done to the code of that time..
    – crip659
    Nov 26, 2022 at 19:52
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    @crip659 I’m sure Harper will be around soon to educate us all about the other benefits, but the lack of GFCI protection is actually one of them: EVSE all have built-in, self-resetting, higher-current GFCI, which avoids nuisance trips, and for temporary trips, also avoids empty car batteries in the morning. Nov 26, 2022 at 20:12
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    The reason code requires GFCI on outlets is they can be used for other stuff than EVs. Welders, stoves, high amp heaters are just a few things that also use that type of outlet/plug, none of which has their own GFCI protection.
    – crip659
    Nov 26, 2022 at 20:24

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Sockets are bad news for EVSEs for a couple of reasons, but the main one centers around a NEC 2020 requirement for GFCI protection on all sockets - even 240V high current ones. Now, an EVSE is itself a smart GFCI - in fact, that's its only function, other than sending a coded signal telling the car how many amps it's allowed to draw from this power point. So a hardwired EVSE aptly meets the NEC 2020 requirement.

Also, hardwiring is required if you do "Share2" style Power Sharing to dynamically share power among multiple EVs. (which is the only way multi-EV home charging should ever be done). And hardwiring is required for 60A or larger, however if your EV is smaller than, say, an up-armored mine-resistant Humvee, you probably don't need that much charge power. (sidebar below).

Now if your permit was pulled and the work done prior to NEC 2020, you can just leave it that way. That particular socket will adapt to ANY socketable need for power - since it has neutral, it can power RVs, be split off to power 4-6 large 120V appliances, kilns, welders, compressors etc. They make adapter cables that plug into this and give you anything. (the UL listed types include appropriate fuses molded-in).

However if you wanted a hardwired EVSE there are several ways to go about it. One is to remove the lid and socket and install a blank cover plate with a 1/2" or 3/4" knockout on it. Then you can come off that with a FMC or wire whip to your EVSE. Alternately you can install the EVSE directly over the face of the blank cover plate so holes align (install THHN extension wires; install box spacer connector onto blank plate, install blank plate on box, install EVSE over box spacer connector, attach wires).

Another way is to install an "extension box" and come out a side port on the extension box and run conduit of your choice to the EVSE. This can be fairly elegant; look at Legrand Wiremold.



(sidebar) It's funny, because within the EV community this is not widely understood, and people put in 14-50s because that plug is provided gratis with their free travel charger because it's the plug at RV parks, duh... and novices see that and think it's the standard EV socket. So the novices have it installed then become EV elders and tell everyone else "do what I did (so I can avoid admitting mistake)". And this becomes a "juggernaut of wrong" and it's interesting to see it reaching government levels. EV's don't even use neutral so using 4-wire cable here is wasted. "Let's waste copper! For the environment!"

But the scary part is: a NEMA 14-50 means you will be charging at 40A or 50A nominal. Most houses do not have 40-50A of spare service capacity. A NEC Article 220 Load Calculation needs to be done for a load that large. A rational approach to EV charging starts at the NEC Load Calculation, determines what is feasible, counterpoints that against the owner's foreseeable need, and takes into account that DC fast chargers are only getting more and more available (as well as high-power level 2 destination units at malls and hotels).

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  • Thanks, Harper, I was hoping you’d stop by. What happened in NEC 2020 that I need to worry about? (This was installed by a licensed electrician, permitted, and passed inspection, in late 2022.) Nov 26, 2022 at 23:37
  • Also I 100% fell in with the “14-50 Is The Standard L2 EV Charging Plug” crowd until I read like a dozen of your EV-plug posts and it finally sunk in. Nov 26, 2022 at 23:39
  • If it passed inspection, you're done. Unless someone ignored rules (and didn't get caught), either your jurisdiction does not yet require GFCI on 240V 50A receptacle circuits or it does and you bought and paid for that GFCI/breaker. Look at the breaker powering this receptacle - if it has a "TEST" button then it is GFCI and if it doesn't that it is not. If it doesn't have GFCI, don't worry about - code changes like this are not grandfathered (I just had a heavy-up and no GFCI breakers put in at all, and while I have the most critical circuits (kitchen and bathroom) GFCI/receptacle Nov 26, 2022 at 23:40
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    @manassehkatz-Moving2Codidact ah, yeah, there’s a monster 50A GFCI breaker in the subpanel. Hopefully I can sell it on Facebook Marketplace along with the receptacle if I do end up hard wiring. Nov 26, 2022 at 23:51
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    @JacobKrall given the breadth of the misconception, I don't think anyone will ever have trouble selling 40-50A EVSE kit. Honestly though I can hardly take credit, Alec @ Technology Connections is doing most of the heavy lifting for me. Nov 27, 2022 at 5:50

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