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Any electricians in the house? Wiring your nema 14-50 gang plug

Any electricians in the house? Is it true you just wire the two "hot" terminals and the "green" ground leaving the "white" neutral alone? Would it be redundant to run both the green/ground and the white/neutral?

NO, you need all 4. 2 hots, one ground, one neutral.

rdalcanto is absolutely correct. If your wire it with three wires as you described it will not be code compliant and will carry with it lots of potential danger/liability.

If you do not feel comfortable wiring the outlet get a licensed electrician. If it is a short run it should run you $250-400..

If you have spent 100K on the car, do not short change your future
power supply costs.

For answers, instructions, etc. etc. check out the "get the charging solution installed" section in the Model S delivery checklist and owners guide

The hot wires by convention are usualy black and red. It does not matter which of the hot terminals they attach to on the outlet, but the white and ground wires must be hooked to their dedicated terminals. They will be clearly marked on the back of the outlet.

If you have a reason to not use a neutral wire, you can install a NEMA 6-50R and get that adapter for your charging cord from Tesla.

Will it work? Yes: the UMC does not require a neutral connection.

Is it to code? Maybe:see for an interesting debate between licensed electricians.

I would install a 6-50. Adapter is 50 bucks from Tesla. Two hots and a ground...piece of cake. Make sure you use at least 6 gage wire.

Let me re-phrase, I am a contractor, I have a nema 14-50 gang plug, a 60 amp 240 breaker and 6 gauge wire. I DID run all four wires but was told by the Tesla "elect service tech" and know I read it somewhere on the Tesla sight not to use the "white or common lead" for the S Model,(I wish I could find it again.) Does anyone know for sure if you use the "common" lead? It's inside the box just waiting to be hooked up along with the "green ground."


Yes, you need to connect the neutral wire to the 14-50 receptacle. Since the wire is already there, what's the down side of just going ahead and connecting it?

The other comments you saw relate to the fact that Tesla doesn't actually use the neutral connection, but other appliances that might be connected to that 14-50 in the future could be significantly damaged and become become unsafe without the neutral connection.

Neutral should definitely be connected on a 14-50, and should be separate from the Ground connection.

schueppert: Thanks for the interesting link... I shudder to think that any licensed electrician would ever take such an unsafe short-cut

IMHO It's very clear that a standard outlet like the 14-50 MUST be wired in the standard way, which includes a neutral connection. To leave out the neutral connection just because some devices may not need it is very unwise because it leaves open the opportunity for other appliances with 14-50 plugs to be severely damaged, overheated, cause fires etc

Just looked at the "High Power Wall Connedtor" Installation Guide

For a 100 amp circuit it recomends two 3 gauge copper wires for L1 and L2 plus a 4 gauge wire for a ground. The neutral is not used. This is similar to a hot water tank installation. If aluminum wire is substatuted, probably 1 gauge will be required.

I don't think aluminum wire is allowed in some city codes; it has a reputation to start fires if not properly installed. Needs to be coated with an anti oxidation compound.

Vancouver, WA

joehuber - I only scanned the material I linked to, but the gist seemed to be that any Level 2 EV charging installation must be dedicated, must be labeled for EV use only, and can't be used for any other purpose. You could argue that installing a neutral "just in case you want to use the outlet for something else" is actually encouraging people to break the code. To be clear, I come down on the side of believing it is best to install a neutral, but I don't think it is as clearcut as you suggest.


Do it your self ! Do it right .
Here is how !
Black or Red are the hot wires which ultimately hook up to the breaker screws in your main panel.
Black or Red hook to the Y or X screws Brass colored screws on each side of the Nema 1450 R device.
White is the ground you have no neutral with 240 volt. Hook the White wire to the bottom straight blade having a Silver screw. Green hooks to the round pin on top. Ground has a green screw.
The green is a case ground or redundant ground wire. It hooks to to the side of the metal box or to green screw on your receptacle or wiring device. The green is also called an equipment ground used to protect you in the case of a broken ground wire. Back up system yes. Some brands do not use colored screws. The NEMA 14-50 device all look the same. holding the pin shaped hole on top ( the equipment ground) the hots are on the left and right . This leaves White wire at the bottom straight pin. Your Tesla mobile connector checks wiring for you when plugged in before you hook it to your car .
You can check it with a voltage meter before use as well you should have 120 volts from each of the two hots on each side to top round pin or the bottom straight pin . Zero from the bottom white to equipment ground .

@schueppert, I don't think that argument applies, as a NEMA 14-50 is NOT a dedicated level 2 charging installation. It is a standard plug. And by code it must be wired in a standard manner. The Tesla UMC isn't even a dedicated level 2 charging installation, it is a device that can be plugged and unplugged into a variety of plugs.

Anyways, regardless of code, it is just common sense that any electrical plug should be wired in a standard way. Otherwise the next house owner will come along and plug something else into the plug and have potentially disastrous consequences is it isn't wired correctly.

Btw, Travis, when you say you have a 60 amp breaker, do you mean a spare breaker not connected to anything else?

@shop. Actually, you are wrong. A NEMA 14-50 outlet installed to charge an EV is an Electric Vehicle power outlet: "Electric vehicle power outlet or EV power outlet — These are essentially the same as EV charging stations except that they terminate in a normal NEMA- type receptacle and are intended to be used with an EV power cord set that is then plugged into an EV receptacle inlet." They have to follow article 625 which, amongst other things, does not permit them to be used for other purposes.

And I don't agree with "regardless of code, it is just common sense...". I believe in following code.

Look guys, I'm not trying to take any short cuts. As I stated before, I already ran all 4 wires 15' from the NEMA 14-50 and the "white or normal" wire is rolled up and not connected in the inside of the box. Please don't tell me to connect it just because there is a connection for it. I've already said I read on the Tesla site not to connect it! I will scour the site till I find it again. Thanks all for your advise and if anyone POSITIVELY knows whether or not to use it please chime in.

I'll accept your apologizes :)

above photo did not work, check out page 4 of this link. It CLEARLY says DO NOT CONNECT THE COMMON WIRE!

The official Tesla guidelines are at:

I'm afraid they do not provide any clarification.

@travis2013 I'm not sure what that document is that you posted a link to. Roadster maybe? Anyway, the correct Tesla document for Model S together with a NEMA 14-50 is the one I linked to above.

@travis2013 I found these statements on page 4 of the document you referenced

"Do not connect all 3 phases of a 3-phase feed."

"Caution: The unused leg (L3 in the illustration) must remain open. Do not connect to a Neutral bar, or to Ground."

Both statements refer to 3 phase power.

Trying to post a picture:

 photo Tesla240_zps7cc009fb.jpg

Yeah!!! Can you explain this?

I had my electrician install a NEMA 14-50 next to a HPWC on the same circuit - partly so that if something goes wrong with the HPWC, I have a back-up, and partly to support the possibility of a second electric car in the garage someday. The NEMA 14-50 was wired with a neutral for code - I believe the Tesla adapter simply doesn't make use of it. The HPWC doesn't use the neutral either. (Now I just need the S! 2 weeks and a bit to go...) But the HPWC tests out and glows green ready and waiting for something to plug in to...

So those instructions are for 3-phase power which is not what I thought you were talking about. Anyway, I would think the wise approach is to take the fail safe approach. Is Tesla does not need/use the neutral then no harm done, but if NEC requires it to be connected and its not, then it could mean problems down the road for you. Most homeowners policies I have seen usually have some kind of statement that says any work done to the house is in compliance with local building codes.


@schueppert : I think you are correct. Those where instructions for the Tesla Roadster. Never heard of a "Home Connector" for Model S.

Some more info:

And yes, comments above assuming 2-phase 240V not 3-phase 208V (most homes are 2-phase and many industrial buildings are 3-phase)

I'm installing my own NEMA 14-50 outlet. Luckily, my electrical panel is exactly where I need it to be, so I only have to run it about a foot away.

All white wires and ground wires are connected to the neutral bar.

Is it ok to connect the white and ground wires from the outlet to the neutral bar? See photos below (hopefully they work) :)

Is it to code to run NM-B into a knockout on the side of the panel without conduit as shown? I'm planning to do something similar but my 14-50 will be accessible from the other side of the wall instead of same side as shown. I thought I had to use a conduit even if it's inside the wall and not accessible.. wrong?
If this is kosher then I will just go this route.

Yes, because it's a main panel. No if it were a sub panel.

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