wiring in 240 Volt outlet for EVSE

[smkettner]

50a outlet needs #8 wire and 40a breaker to meet code.

For a receptacle on a dedicated circuit, the only NEC requirement is that the receptacle rating is no less than the circuit rating.

I don't think that is true even if safe for a specific use.

Review Table 210.21(B)(3) and related description. Best to have the city inspect or at least get the guidance of an electrician.

In your own home it should be fine. But for public use or when you sell the home circuit should be brought up to code.

 

[wwhitney]

For a receptacle on a dedicated circuit, the only NEC requirement is that the receptacle rating is no less than the circuit rating.

I don't think that is true even if safe for a specific use.

Review Table 210.21(B)(3) and related description.

Table 210.21(B)(3) does not apply to a single receptacle on a dedicated circuit. See 210.21(B)(1).

Cheers, Wayne

 

[johnrhansen]

So if one were to fudge and put a 14-50 on a 2 wire circuit., what would be safer: omitting the neutral, or simply connecting both the neutral and ground terminals to the ground wire? It worked for years on old style 10-xx receptacles for ranges and dryers. I know its not code and I would never do it for anything but my own project, and I would remove it when I sold. Sounds easier just to build it to code.

 

[UBUYGAS]

I bought the Leviton at home because I like Leviton and when I bought it it was brand new technology and had a 3 year warranty. 17 months ago the options were slimmer.

http://www.polkaudio.com/forums/showthread.php?147882-Bought-a-New-Car!&p=1916248&viewfull=1#post1916248" onclick="window.open(this.href);return false;


I also sent my Panasonic EVSE to http://www.EVSEupgrade.com" onclick="window.open(this.href);return false; and I carry that with me all the time:

http://evseupgrade.com/?main_page=product_info&cPath=1&products_id=2" onclick="window.open(this.href);return false;


I installed a 30 amp twist lock L6-30R at my Parent's house when I visit them:

http://www.mynissanleaf.com/viewtopic.php?f=37&t=15405" onclick="window.open(this.href);return false;


And I bought one of these: http://tinyurl.com/quick220" onclick="window.open(this.href);return false; so that I can create a 220 line at a friend's house who does not have a 220 line and charge 3X fatser than 110!


Sal

A 30 amp EVSE is fine for the Leaf - and most likely what I'll end up installing - I was just looking at options for "future proofing" a little. But there is a significant price jump from the 30 amp units to the one 40 amp unit. As battery technology improves, leading to larger capacity batteries with list internal resistance (less heat when charging), I expect EVs to start coming with more powerful onboard chargers.

 

[mctom987]

So if one were to fudge and put a 14-50 on a 2 wire circuit., what would be safer: omitting the neutral, or simply connecting both the neutral and ground terminals to the ground wire? It worked for years on old style 10-xx receptacles for ranges and dryers. I know its not code and I would never do it for anything but my own project, and I would remove it when I sold. Sounds easier just to build it to code.

2 wire circuit can't even power any device designed for a 14-50. Unless you meant 2 conductors, and a ground.
The ground isn't designed to carry current, and for high power circuits, it's often a lot smaller. 4-4-4-6 SER, for example. Conductors are #4, and the ground is #6.

That said, both the neutral and ground are grounded, so it should be safe to bond them at the outlet, just not up to NEC specs. The neutral is only used for 120V connections, so in some cases (like an EVSE), it's perfectly safe to omit it entirely. One should never have an outlet like that omit the ground. If something should short, you can become the grounding path.

 

[wwhitney]

So if one were to fudge and put a 14-50 on a 2 wire circuit., what would be safer: omitting the neutral, or simply connecting both the neutral and ground terminals to the ground wire?

What is safest is to use the proper receptacle, a 6-50. Never rebond the ground and neutral downstream of the main service disconnect, it is unsafe as it turns the ground into a current carrying conductor, potentially energizing the chassis of equipment with a subsequent fault. If you twisted my arm and made me use a 14-50 receptacle for a 240V only circuit and load, I'd permanently block the neutral hole on the receptacle and remove the neutral pin on the plug.

Cheers, Wayne

 

[msbriggs]

I see that you're reluctant to go with a "kit" EVSE like openEVSE or Juicebox, but the advantage they give is more than just their low cost. They're also way better than any "off the shelf" options in terms of portability and adjustability. Adjustability is a big plus if you ever want to take your EVSE with you to charge on the road. Your 30a EVSE is no good if you're at a friend's house or vacation rental with a 30a dryer outlet you could plug in to (you'd need to derate to 24a) or if you bring a quick220-style device to get 240v from two 120v outlets (derate to 12a or 16a).

Also, if you're comfortable doing the wiring for your circuit, you should have no problem whatsoever putting together your own EVSE, and you can get either type pre-assembled if you prefer anyway. Plus, UL listing is worthless as a guarantee of actual safety, although it may help with insurance in the exceedingly rare event of a fire attributable to the EVSE. Note that many of the commercial offerings aren't UL listed either, while the most dangerous one seen yet (Blink) was. If a fire does occur, it's much more likely to occur in the in-home wiring. If you're comfortable enough to do that yourself instead of going with a pro, why not put your EVSE together too? In all likelihood it'll actually be safer, since you'll know how it operates and can carefully inspect your own workmanship, rather than getting a "black box" that you never open.

I admit, you make some very good points there. I'll have to think about this some more....

I've thought some about going with the Juicebox in part because I've never used an Arduino before, and wouldn't mind an excuse to fiddle with one.

On an unrelated note, but something people might find interesting - several years ago I restored a 1973 GE Elec-Trak E-15 electric tractor. Here's a picture of it when I got it:

And after stripping it down to the frame, getting it working, and rebuilding it:

For the most part, the electronics are all original (except for a few relays, and one capacitor that had blown). So - a 40-year old electric vehicle still running on mostly original parts. The body needed serious attention, but once I found the blown capacitor on one of the breadboards and replaced that, it started working fine. Point being - electric vehicles can be pretty darn durable.

 

[msbriggs]

However, to the OP, I caution against installing a 4 wire receptacle (14-50) with only 3 wires connected and omitting the neutral. I haven't checked the NEC, but it sounds like a future problem. At the very least if you do this, label the receptacle "240V only, no neutral".

Cheers, Wayne

Thanks Wayne, that's a good point. One of the reasons I opted for the 6-50 instead of the 14-50 was in fact that I could get by with just 6/2 cable instead of 6/3 - and the cable is the most expensive part of putting in the outlet. That's one concern I had with the 6-50 to 14-50 adapters. Of course, 14-50 receptacles are really intended more for "appliances" like washing machines and ovens, where there is more focus on the potential for the hot wire to short to ground.

 

[johnrhansen]

All I was saying is that omitting that neutral is a very unsafe thing, and that connecting it to the ground is safer. But yes, even half right is still wrong. Still, for years the old style 10-30 dryer plugs ran the tumbler and timer motor return through the ground. Yes, maybe it was a neutral wire, but in most house's panels where that wire was connected neutral and ground bars are connected together anyway, and usually it was a full sized wire. The only difference is lack of insulation or green insulation instead of white. It was allowed by code up to several years ago. Even today when you install the a 4 wire pigtail on a range or dryer you need to remember to disconnect the neutral terminal from the chassis ground. Unless you are dealing with 2 leg 3 phase, the neutral current is usually quite low compared to the mains.

 

[Nubo]

I know its not code and I would never do it for anything but my own project, and I would remove it when I sold. ...

Yeah, I've contemplated that approach when looking for shortcuts, but you have to ask yourself. What happens if you get run over by a truck and they sell your estate, to someone who has no idea that things are not as they appear?

 

[mctom987]

I know its not code and I would never do it for anything but my own project, and I would remove it when I sold. ...

Yeah, I've contemplated that approach when looking for shortcuts, but you have to ask yourself. What happens if you get run over by a truck and they sell your estate, to someone who has no idea that things are not as they appear?

The way my 14-50R is going to be wired will look like a very amateur job. If the dangly wire hanging from the ceiling isn't a dead giveaway, I'm sure they'd find another way to do something crazy.

FWIW, all outlets should be verified and tested before use. This is especially true on the L1 EVSE provided, as it can easily trip breakers if it's not on a dedicated circuit.

 

[TonyWilliams]

Of course, 14-50 receptacles are really intended more for "appliances" like washing machines and ovens, where there is more focus on the potential for the hot wire to short to ground.

The reason for 14-30 or 14-50 is for both 120 volt (clock, controls, etc) and 240 volts (motor, resistance heater, etc).

 

[QueenBee]

Of course, 14-50 receptacles are really intended more for "appliances" like washing machines and ovens, where there is more focus on the potential for the hot wire to short to ground.

The reason for 14-30 or 14-50 is for both 120 volt (clock, controls, etc) and 240 volts (motor, resistance heater, etc).

Yeah, the issue it solves over the old dryer receptacles 10-30 is that when sharing the neutral and ground there is a problem if the ground/neutral combined wire were to become disconnected. The scenario being a dryer's metal frame is grounded and a dryer has timers/control circuitry/etc which is only 120 volt so they would connect it to one hot but when there was only a combined neutral/ground if that were to become disconnected the frame would become energized and thus touching it could allow you to become the path for the neutral. 14-30 solves this by have separate wires for the ground and neutral.