Question about installing a 240 outlet

Question about installing a 240 outlet

I'm trying to get prepped and make sure I have everything covered for my MS and was wondering if anyone had any more details about installing the 240v outlet. Do I only need to tell the electrician that it is a NEMA 14-50 outlet? Or any other details?

Also, if anyone has done this, what was the rough cost?


David Trushin | 03. April 2013

there are a lot of threads on this already. Use to search. there is also a schematic for the outlet on the manuals page.

biggator | 03. April 2013

14-50 is fine.. I ended up with a 6-50 (the existing conduit would only fit a 3-wire) which works the same, as the Tesla doesn't use the neutral anyway.

Cost will vary based on how far the outlet is from your service panel (copper is expensive).

FWIW - the people that Tesla sent to me quoted me almost 3x what a local master electrician did.. so get 2 quotes. I had the local guy do it.

riceuguy | 03. April 2013
trydesky | 03. April 2013

Be sure to point out that the ground lug goes at the top. Even though I gave my electrician the printout of the above link, he still managed to overlook it. It's an easy fix, but why not do it right the first time :)

NKYTA | 03. April 2013

@ trydesky
Heh. My electrician did the same. Turns out it worked for the best, as I feed the extra cable length over a hook up by the ceiling and have just enough to plug her in.

David Trushin | 03. April 2013

I also have it upside down, but like it, since I wrap the cable around a hose caddy above the outlet at the right height so I can see if it is charging when I look into the garage to admire my car

dstiavnicky | 03. April 2013

I recommend running #6 wire from the panel. And change the breaker to 50Amp. This will ensure a constant safe 40A charge rate.

Andrew_OH_S60andS70D | 03. April 2013

I agree with the comment on getting more than one quote. Something that will affect the cost is the location of your current breaker panel and if there is enough room to install another breaker in the existing panel.

Luckily, my panel was in the garage, and I had just swapped out my electric oven/range top to gas. This left a 220 breaker free. The entire cost was around $150.

I do not have my high power wall connector yet, and I'm not really sure I will need it. I also had a plug installed at work. I plan on upgrading that to the HPWC and offering it to Tesla owners that happen to be driving down I-75 that need a charge.

amits32 | 03. April 2013

Tesla recommends a Nema 14/50 outlet. I bought mine at the local hardware store for about 10 bucks along with a 8 gauge 4 wire romex cable that cost about 170 for 125 feet. Some had recommended the 6 gauge wire but all the electrician's I talked to said the 8 gauge should be enough.

All depends on how far away you need to put the outlet from the breaker panel. Installation cost about 300. Total cost was around 500 in my area. I live in Houston. This was about half the cost some of the other electrician's in my area were charging including the one Tesla contracted out.

I would definitely get a few quotes.

Longhorn92 | 03. April 2013

I had about a 100' run from the panel to the garage outlet. With 200A service and plenty of room in the panel, there was no need to upgrade the panel or wiring to the panel. Also, the electrician was able to use my existing conduit (small outside extension of conduit to house ground and minimal additional conduit on the outlet side). It cost me $750.

I received four quotes. The Tesla-recommended folks (Mr. Electric) were by far the highest and the local electricians the lowest. Part of the reason for the big difference in quotes was that each electrician had a different solution of how to do it. Some of them had easy solutions using much of the existing conduit while others wanted to start from scratch from the panel all the way to the garage. Definitely get several quotes!

Brian H | 03. April 2013

David T.;
It should be installed sideways to suit all tastes. ;)

Darmok | 03. April 2013

This is from FlasherZ's FAQs over on TMC regarding wire size for a 14-50 outlet:

For “Romex” (NM-B cable), it must be sized for the 60 degC rating. This means that 8/3+ground NM-B may not be used for 50A, and 6/3+ground NM-B must be used. Note that type NM cable must be protected from damage (e.g., must be run inside a wall) and cannot be exposed. If you must run wiring on the outside of a wall, below 7' above the floor, you must use conduit. Type NM cable may be run in conduit as long as it does not run outside.

rochec | 03. April 2013

Thanks all, incredibly helpful responses. Can't wait to get my MS!

solarpowered | 04. April 2013

The biggest potential surprise would be is if you have to upgrade your electrical service. Modern homes have 200 amp service. My house was built 19 years ago, but only came with125 amp service. If your service is underground, it could really be expensive. My overhead service cost $2,000. The electrician through in the NEMA 14-50.

kyleket | 04. April 2013

Any suggestions on the height of the 14-50 outlet itself? I've had my electrician install everything EXCEPT the actual outlet, which he will come and install after my S arrives.

I'm assuming waist-high would be just fine, but am open to the idea that there might be something I'm not taking into account.

ir | 04. April 2013

Kylekt, got dinged by inspector for outlet being too high (shoulder / head high). There are Americans with Disabilities Act regulations on height (40 something inches) from the ground don't have building code handy. Imagine somebody in a wheelchair trying to plug the charger in. Waist high sounds about right.

JDPink | 05. April 2013

I had my 14-50 outlet installed yesterday (Los Angeles) and the cost was $500 for the outlet, next to the panel, as well as the electrician building me a 50 ft. extension cord.

kyleket | 05. April 2013


Thanks. Waist high sounds good to me.

nickjhowe | 06. April 2013

@kyleket - the cable is 20' long. Every foot up the wall you place the outlet is a foot of reach you are taking off it. Measure the real world distance from your outlet to where the charge port is on the car, which way round you are going to put the car in the garage (forwards, backwards, both?), whether you want to be able to charge outside and go from there. Also note the center of the 'box' on the UMC is about 18" in, so also figure out whether you want it hanging down the wall, to be supported on something, or lying on the floor.

Brian H | 06. April 2013

No, study the Pythagorean Theorem. The cord reach varies as the hypotenuse, which is the sqrt of the sum of squares of the other two sides, and the movement up and down the wall has negligible effect.

shop | 06. April 2013

@brian, that's assuming you have the corded suspended in the air. Some people like to have it laid on the ground. Given how my dog managed to give it a good yank one day because it was suspended in mid air and she didn't see it, laying it on the ground is a safer option for me.

Anyhoo, here's a picture of what my setup looks like. I had the electrician run an extra 20A circuit to power the four 120V plugs you see below the nema 14-50 socket for all our battery powered scooters, bikes, etc. And I've got a $10 home depot hose reel above the nema 14-50 to hold the slack.

Joseph1ng | 06. April 2013

SolarCity did mine in Honolulu for $700. The initial quote was $400 but then the wiring condition is such that they had to reroute some 200 ft of cable around the house to reach the garage. It is quite reasonable. Using PVs to fuel the Model S is ideal - saving all gas charges, and time at gas lines. Getting really close to zero carbon footprint.

nickjhowe | 07. April 2013

@Brian - another example of theory over real world. Maybe you should get a car. As @shop says I don't want my cable suspended in mid air. It hangs down the wall then across the floor - so it matters a lot.

Brian H | 07. April 2013

Well, if you insist on taking the long way 'round ...

bsimoes | 08. April 2013

@shop--thanks for the picture; for some reason, I never considered having the hose reel over the plug, but being mine will be an outdoor setup, it seems that it would protect the plug just a little bit more.

@ir--"got dinged by inspector for outlet being too high (shoulder / head high). There are Americans with Disabilities Act regulations on height (40 something inches) from the ground..." This was really surprising to me; do you mean to say that this is true even if it's a private home??? If I own my home and I want a plug higher than that (I can't imagine I would) I might get dinged?