Is there a way to get GFCI protection on a circuit greater than 20A (or 120V) other than with a GFCI breaker? (I know you can do outlets and dead-front switches up to 20A on 120V.) Just turning things over in my brain for future outdoor electrical stuff, like e-vehicle chargers.
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2What's the problem with using a breaker?– isherwoodMay 5 at 12:50
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4Note that vehicle chargers often incorporate GFCI, so you may not need to do anything else– keshlamMay 5 at 13:03
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@isherwood no real problem, just spitballing.– HuesmannMay 5 at 13:04
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@keshlam just thinking about adding another 120V circuit to the location. But I guess that could be done with the standard GFCI outlet/switch.– HuesmannMay 5 at 13:05
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2I'm interested in why? Sometimes, if you describe "why" in words out loud ... then you imagine yourself trying to build and sell a product to meet that need ... you can also imagine yourself losing a lot of money.– jay613May 5 at 13:38
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5 Answers
You can't, because they are not made, so it's a breaker or nothing.
Well, in the specific case of vehicle charger, you hardwire them and they have one (that's smart enough to self-reset) built in, so if you don't use a receptacle to PLUG them in, you're good.
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1My electrician told me a horror story about a customer last year who insisted on a large receptacle for future EV, in a jurisdiction that at that time already required GFCI for large 240V receptacles, which meant GFCI/breaker. Which my electrician had a crazy time sourcing due to manufacturer issues (not only "the supply chain" but also breakers not exactly fitting the panels they were supposed to fit). He eventually got it resolved properly, but if the customer had either picked an actual EVSE (and then hardwired it) or run the wires for future hardwired use and not with a receptacle May 5 at 13:54
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2Yeah. For future use, just run the wire, terminate iit in a box on either end, and wait. Or, perhaps better, run conduit with a pull rope to boxes, and then you don even have to guess wire gauge in advance.– keshlamMay 5 at 14:04
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@keshlam after reading the responses here and doing some additional research, that's probably the way it's gonna go.– HuesmannMay 5 at 19:54
Is there a way to get GFCI protection on a circuit greater than 20A (or 120V) other than with a GFCI breaker?
Well, this might change, because NEC 2020 and NEC 2023 impose GFCI requirements on many 240V circuits. However, (and this is the part that is an off-topic shopping question), the current products being offered by GFCI manufactures, which exceed 20A, only come in TWO types:
- GFCI breakers
- Car "chargers" = EVSE (Electric Vehicle Supply Equipment)
Just turning things over in my brain for future outdoor electrical stuff, like e-vehicle chargers.
If it's an EVSE powering a J1772, Mennekes or Tesla port, it will have "smart GFCI" built right into the EVSE. So adding a "dumb GFCI" to those circuits is a waste of time and will defeat the smart GFCI (ground faults may trip all GFCIs, so the EVSE is now stone dead and cannot self-reset and cannot notify you).
However, if the EVSE is not installed thoughtfully, a dumb GFCI may be necessary. For instance, if it is connected plug-and-socket, the socket must be GFCI protected. Better to hard-wire the EVSE, even if that concept feels a bit alien. This requires a wall-mount style EVSE intended for permanent installation.
Note that many EVs ship with a "travel" EVSE that is intended for use traveling, for opportunity charging on the road, and as such, contains the sockets found on road trips: the normal one, and the NEMA 14-50 RV (Recreational Vehicle) socket found at RV parks. It was never intended for daily at-home charging, but its existence confuses the heck out of people, and fills their heads with wrong ideas.
answered May 5 at 21:04
Harper - Reinstate MonicaHarper - Reinstate Monica
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Thanks, Harper! I'll add that the reason I'm thinking to do this outdoors (rather than in the garage) is the risk of vehicle fire. That may or may not still be a concern by the time I ever get an EV—who knows if things will improve in this area—but for the moment, I would sleep better knowing the car isn't gonna burn the house down.– HuesmannMay 6 at 12:55
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@Huesmann Interesting concern about vehicle fires. Honestly I spend all my time thinking about service panel fires due to putting unnecessarily large EV charging on an already-loaded panel. May 6 at 20:07
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It's not just fires that's a concern of the increasing adoption of EVs, There are issues such as parking structures not being able to handle the weight—what happens when cars weight 1000 lb more than they used to? (Obviously not a concern for SFH surface parking.)– HuesmannMay 7 at 12:38
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@Huesmann LOL were you not paying attention? That already happened, not EVs' fault. Automakers convinced people to buy these monsters so they could sidestep smog/MPG standards. Even econoboxes got fat: my last 3 cars weigh <2100 lb but post-2000 even econoboxes weigh 3100-3500 lb. depending on trim (read: automatic trans and A/C, which everyone gets, of course). So that ship has sailed. If anything, EVs will lighten vehicles by deleting the reasons automakers push SUVs. May 7 at 20:07
TL;DR GFCI/breaker for 240V and 240V/120V has a number of advantages in design and production and little disadvantage (except cost) in use, so unlikely to see a lot of GFCI/receptacle options in the near future.
As already noted, these things are nearly unobtainable. But I think it is a matter of supply and demand, not any inherent complexity.
First key point: NEC 2020 does require GFCI for 240V receptacles. See this article for some details. Old stuff all grandfathered, but in new homes (or major renovations) you're going to need GFCI for "everything" in the key locations that have 240V or 240V/120V receptacles and appliances. That includes clothes dryers (laundry = wet area = GFCI in general so now GFCI for 240V), some cooking equipment (which is all the more reason to hardwire where practical), a lot of HVAC (inside not required if, as usual, hardwired, but outside now required for 240V even hardwired), etc. Exceptions are, at least for now, indoor hardwired appliances (oven, water heater, HVAC air handler) and hardwired outdoor that include GFCI in the appliance (EVSE).
Many jurisdictions are being deliberately slow to adopt these particular sections of NEC 2020 due to cost and problems getting the right parts. GFCI/breakers are the only option for most people, most of the time, for 240V any size, 240V/120V any size and 120V > 20A, and that can be a real problem with older panels and even with some recent panels (as my electrician can attest).
Honestly, I think this is a supply/demand issue, not a technical issue. It is easier for a panel manufacturer to make (and test, certify, etc.) one 30A GFCI/double-breaker than for a receptacle manufacturer to make two separate types (14-30 240V/120V and 6-30 240V), plus the GFCI/breaker will work for the hardwired appliances (now required for outdoors though not for indoors), and it may be a bit of a challenge to fit a 240V/120V GFCI/receptacle in a standard box.
Volumes are higher too. GFCI 15A/20A receptacles are "everywhere", so true volume production has kicked in to lower the cost per unit, even after including features such as automatic testing. A typical house will have at least 5 120V circuits requiring GFCI (kitchen x 2, bathroom, laundry, outdoors) and often several more (basement, extra kitchen and bathroom, etc.), all of which (except outdoors, where indoor location of the GFCI away from the weather is a plus) benefit from convenient point of use reset. Unlike kitchen, bathroom and outdoor receptacles, all of which are subject to occasional trips due to real-world problems (getting things wet while working in the kitchen and bathroom and outdoors are normal situations), 240V GFCI are likely to go years between trips, so convenient reset is a non-issue.
Back to the technical aspects: A 240V (hot/hot no neutral) GFCI/receptacle should be no more expensive than the equivalent 120V (hot/neutral) GFCI/receptacle, except for handling higher current. A 240V/120V (e.g., 14-30, hot/hot/neutral) GFCI/receptacle has to handle neutral, so the detection is more complex, but arguably the cost should not be more than double, except for handling higher current. An ordinary 120V receptacle (non-GFCI, no USB, etc.) might range from $1 to $5. An ordinary 240V/120V receptacle is more on the order of $10 to $30, depending on brand and quality. In fact, most 120V GFCI/receptacles that I know of include a better quality receptacle as part of the product - i.e., you don't get a $10 GFCI/receptacle that is based on a $1 receptacle, it is based on the $3 receptacle. With the cost on 240V/120V receptacles starting higher, and ranging even higher, GFCI/receptacle would either go really high cost or end up hiding the lower-quality of the rest of it to get a lower price-point, which is trading one problem for another.
But on GFCI/breaker, most of the high-current issues are handled pretty easily (e.g., you don't have user accessible contacts to deal with - everything is screwed in place), and in fact what you will typically find (quick Home Depot search, YMMV) is that within a given brand, a 2-pole GFCI/breaker will cost incrementally more than 2 single pole GFCI/breakers (i.e., more than 2x but less than 3x) and a high-current (e.g., 50A vs. 20A) GFCI/breaker will cost the same or very little more than a low current breaker. Because the panel manufacture can get everything done as one nice big batch for production, certification, etc.
answered May 5 at 15:57
manassehkatz-Moving 2 Codidactmanassehkatz-Moving 2 Codidact
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FWIW, I wasn't planning to stick an outlet on the end of this thing, the Q was more of curiosity of "they have these things for 20A circuits, I wonder why you don't see them for 240V?" But I guess it's because not many homeowners plug anything requiring 240V outdoors.– HuesmannMay 5 at 19:56
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True about outdoors. But would apply equally to 240V in a basement or workshop or garage - all of which are a bit more common (240V woodworking equipment, etc.). May 5 at 20:00
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2a point showing that it's clearly just a supply-chain issue and not a technical one is the obvious fact that Europe has 240V GFCI breakers all over the place May 5 at 21:17
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@user253751 Basically true. Except one key difference: A 240V European GFCI (RCD they call them, but basically the same thing) is checking two wires, while a US 240V is usually 240V/120V and checking three wires. May 5 at 21:38
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1@manassehkatz-Moving2Codidact: That's true, but I don't think checking three wires is that much more complicated: most GFCI designs I've seen pass the two wires through a current-sensing coil; in normal use the currents are opposite so cancel out; if there is any current detected it indicates an imbalance so the GFCI trips. Moving to three wires just means passing all three wires through that coil (ie it doesn't trip as long as any current flowing through one hot returns through either the other hot or neutral). But as you say, supply and demand makes all the difference :)– psmearsMay 5 at 22:02
FYI, a spa panel can be sourced for $100-$150 and most of them come with a GFCI breaker already installed. It doesn't looks as nice as a plain plug on/in the wall, but it's definitely cheaper.
You can add one on the plug end... but I hope you've got a big budget. We're talking about a commercial-grade device that could cost more than your charger (that one is about $450). Contrast that with this 30A 240v GFCI breaker at a big-box hardware store for $130.
What makes this complex is how 240v works. A GFCI typically watches the hot and neutral. If they go more than slightly out of balance, it trips so you can't get electrocuted. A 240v setup doesn't technically need a neutral. As I noted elsewhere, there just aren't a lot of use cases for 240v GFCI as a result (and NEC doesn't mandate them either). With the market limited, anything that does exist will be for industrial setups where you are spending a ton on electrical anyways (when you're spending $50k on electrical, a $450 point-of-use GFCI makes more sense).
