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If such a receptacle exists, what is the (US) NEMA designation for a 250V receptacle with a terminal on the back for hot#1, and one for hot#2, a ground terminal, and also a place to attach neutral, where the receptacle is prong-compatible with an L6-20P plug? And are such receptacles available with GFCI protection? Or is neutral not needed/available?

mr blint
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3 Answers3

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NEMA type 6 is for hot, hot, ground. Used for welders, heaters that do not require neutral.

If the device(comes with NEMA 6 plug) and you have a three wire cable plus ground, then you just cap/wire nut the neutral wire.

You want to look for NEMA L6-20R receptacle.

For devices using two hots, neutral and ground you look for NEMA type 14 plugs/receptacles.

crip659
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    You can put both NEMA 6-20R and NEMA 14-20R receptacles (with or without the L for locking) on the same GFCI breaker if you have some devices that need one and some that need the other. Just don't connect the Neutral to the NEMA 6 devices. – Ecnerwal Mar 29 '23 at 14:02
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If such a receptacle exists, what is the (US) NEMA designation for a 250V receptacle with a terminal on the back for hot#1, and one for hot#2, a ground terminal, and also a place to attach neutral, where the receptacle is prong-compatible with an L6-20P plug?

No such thing exists. The NEMA L6-20 plug/socket specification excludes neutral. Many 240V loads do not need neutral. (A/C, water heater, EV charging, well, compressor, welder). If you ran cable w/ neutral to the socket box, then just cap off neutral when you wire the socket.

If you have an application that needs neutral (dryer, range, RV) ... then you need to use the NEMA 14 family sockets.

And are such receptacles available with GFCI protection?

Absolutely not. There is no 240V GFCI receptacle anywhere on the market*. If you need to provide GFCI protection to one, you'll have to learn more about how GFCI works (hint: it's NOT a receptacle, that's just a way that some GFCIs are packaged). You use a GFCI breaker for that, they're around US$100.

* Except for the Tesla or J1772 "Fetch" connector used for EV charging. The EV wall unit contains a smart GFCI. As such, a second dumb GFCI should not be used on hard-wired EV connections.

Harper - Reinstate Monica
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  • My situation is a garage, and I was reading on the HomeDepot website: "GFCI protection is required for all 125-volt to 250-volt receptacles rated 50 amps or less, not exceeding 150 volts to ground, supplied by a single-phase branch circuit in the following: Basements, all areas, including unfinished portions Bathrooms, all areas Crawlspaces, all areas Garages, including service bays and similar areas, but not show rooms and exhibition halls" so I though maybe there was a 250V outlet with built-in GFCI analogous to the 120V version. Does a home garage count as a "garage" in that sense? – mr blint Mar 29 '23 at 19:03
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    @mrblint "Maybe there was a 250V outlet with built-in GFCI" (implied: that would be 1/3 the price of a GFCI breaker) - **nope. Not yet, anyway.** Note that the 240V GFCI requirement only applies to states which adopted NEC 2020 and did not delete the requirement (some did, because it has *serious* issues). I suspect when such a 240V GFCI *non-breaker* arrives, it will take the form of a **deadfront** so they don't have to make a separate version for 6-15, 6-20, 6-30, 14-30, 6-50, 14-50, L6-15, L6-20, ad nauseum. – Harper - Reinstate Monica Mar 29 '23 at 19:12
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    @Harper-ReinstateMonica: What's surprising to me is the EU doesn't have them (unless something changed since last year they don't). – Joshua Mar 29 '23 at 21:51
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    @Joshua Most EU setups use whole house RCCDs as the main breaker (https://diy.stackexchange.com/questions/187144/are-whole-house-gfcis-legal-in-the-us), so there is minimal to no market for outlet GFCI/RCDs. – user1937198 Mar 29 '23 at 22:55
  • @user1937198: "US breakers are focused on human safety, they trip at 5 milliamps. Europe only is after parallel arc faults, so they threshold at 30 milliamps" Not the same thing at all. – Joshua Mar 29 '23 at 23:10
  • Here in the UK you can buy both 13A sockets with RCDs and "Combination units" that combine an industrial socket with a RCD. Both are relatively unusual though. – Peter Green Mar 29 '23 at 23:11
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    @Joshua At least in the UK 30mA RCDs are used for personal protection. I don't know where this idea that "Europe is only after parallel arc faults" comes from. – Peter Green Mar 29 '23 at 23:14
  • One thing is that in Europe, countries generally have one 3kW rated socket to cover the role of the 5-15, 6-15, 5-20, 5-30, and 6-20. So there is less of an issue with different outlet types. – user1937198 Mar 29 '23 at 23:16
  • @PeterGreen: I don't know either but I know that 30mA won't fly here if something is required to have GFCI protection. – Joshua Mar 30 '23 at 00:04
  • @PeterGreen It's more a case of they know they should do *something* for personnel protection, but they already have this huge installed base of 30mA RCDs, so they're like "it 6mA really *so much better than 30mA* that the huge cost of fitting per-circuit 6mA RCDs **is the best use of money to improve safety?**" And the answer is understandably "no". – Harper - Reinstate Monica Mar 30 '23 at 00:33
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To answer the second part of the question I've never seen a 250V in-wall GFCI receptacle. Pretty sure they're not made. You need to use a GFCI Breaker or an expensive portable plug-in GFCI outlet.

jay613
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