Master Thread: Definitive 14-50 NEMA Outlet Guide

[Gauss Guzzler]

If you want to DIY you can buy 6/2 Romex by the foot from Lowes for a few dollars and pair it up with a "Type BR" breaker.

If you want it to pass inspection when you sell the house, the Romex has to be clamped at both ends, can't be exposed, and can't be in conduit, only stapled to the studs inside a finished wall. If you need it exposed you'll need to use individual red/black 6 AWG "THHN" wires in 3/4" conduit with a bare 10 AWG ground. If you want to DIY the conduit it's easy to cut with a hacksaw (then deburr with a screwdriver or something) and there are various elbow fittings you can buy to make corners or use flexible conduit if preferred, though flexible conduit is not as easy as it sounds.

Lastly, if you need a new outlet box because that one was hacked together from an extension cord, the simplest solution is a 4" square box with a round cover and either a suitable Romex cable clamp or conduit fitting.

 

[davewill]

If you need it exposed you'll need to use individual red/black 6 AWG "THHN" wires in 3/4" conduit with a bare 10 AWG ground.

He could also use MC cable.

 

[CyberGus]

That $400 install is starting to look pretty good about now, lol

 

[Feathermerchan]

The prev owner installed 70A breakers because welders can draw large currents to start.
That does not make it OK in any way. Follow what others here have said or hire an electrician.
Obviously the house electrical was not inspected prior to purchase.

 

[zannman]

Holy repeated post!

What bothered me most about the breaker box the first thread you posted this in was that the now known 8AWG cable in the 70A breaker looks exactly the same size as what's in the 50A breakers presumably for your range and other things. We originally thought and hoped it was 6AWG. 8AWG is typically only good for 40A. You might find that you have issues elsewhere in the house when you involve an honest electrician.

 

[royinla]

Thanks all - issue resolved (well it did cost $400), but the electrician confirmed the original setup was wrong and dangerous...I asked to keep a 6-50 outlet, and he re-wired everything using 6AWG, 50A and neutral wire as well. He also put a new box around the outlet. Everything seems to be great and up to code. Now I just need the car...lol

 

[Feathermerchan]

Good job. Better to be safe. BTW I have found that charging at 30A is plenty fast enough.

 

[JCtx]

Got my 14-50 outlet installed today. Electrician used Romex cable, but 6AWG, so more than enough for 32A max from the mobile cable. He put 50A breakers, since that's the rating of the outlet, but said the wires are supposedly good for 60A, so plenty for my application. The good news is the outlet is right behind the fuse box, so the length of the wires is probably 2'. Finally, he didn't use a Leviton outlet, which is good. But it wasn't one of the best mentioned either, but looked fine. Haven't used it yet, but will check to see how hot it gets when I use it for the first time, probably tomorrow (I'm going to hook the car every other day, and max it to 80% when not traveling). Also installed the wall kit, so everything looks nice and tidy .

 

[davewill]

Electrician used Romex cable, but 6AWG, so more than enough for 32A max from the mobile cable. He put 50A breakers, since that's the rating of the outlet, but said the wires are supposedly good for 60A, so plenty for my application.

Sounds great, except that with Romex, 6awg is only good for 50a, not 60a. With such a short run, dude should have either used 4awg, or THHN in conduit. However, if you aren't ever planning on converting to 60a, then no problem.

 

[Rocky_H]

Got my 14-50 outlet installed today. Electrician used Romex cable, but 6AWG, so more than enough for 32A max from the mobile cable. He put 50A breakers, since that's the rating of the outlet,

Cool--yep, that is a perfect setup for a 14-50 outlet.

but said the wires are supposedly good for 60A,

It's not. Jeez, what is with some electricians failing so badly at such basic things?

 

[gilscales]

I installed the Hubbel 9450 in preparation for my delivery and have it connected to a 40Amp breaker. I planned on setting my Grizzl-E charger to 32A as I read you can only use 80% of the capacity of the breaker for EV charging. The inspector when he came to my house actually wrote 32A MAX charging on my outlet.

As others have mentioned, I'll be charging overnight and probably could reduce the 32A output to the next lower setting, as I won't need the car until the morning. I only have 100A service in my house.

Located in Canada

I have my charger set at 40A and just set the car at 20 to 24 amp because I don't need to charge any faster 95% of the time, 32A is all most would ever need and its easy to dial it back from the touch screen

 

[goldenstate01]

So I just bought a brand new home and the garage came wired with 8/2 wire but no outlet. I plan on installing a NEMA 6-50 with a 40a breaker since the wire is only 8/2 and I will be charging at 30amps. Should be okay right?

 

[jeremymc7]

You’re saying there are wires in the garage with no outlet and wires in the panel with no breaker ???

Seems odd. I mean mine is like that. But only because I had an electrician disconnect a dedicated arc welding plug in the garage so I could free up breakers in the panel to reuse for a home remodel since I don’t use an arc welder.

You need to have someone check and make sure there is NOTHING else on that line as well before you go any further.

Someone else will chime in here but I don’t think you should be putting a 50 amp breaker in the wall with a 40 amp break and then charging at 30 (???) amps. You need a different set up.

 

[Sophias_dad]

So I just bought a brand new home and the garage came wired with 8/2 wire but no outlet. I plan on installing a NEMA 6-50 with a 40a breaker since the wire is only 8/2 and I will be charging at 30amps. Should be okay right?

The 40 amp breaker is appropriate for the wire gauge, even if its NMB wire. For EV charging(continuous) purposes, the EV should only draw 32 amps maximum(40 times 80%) to account for long term wire/breaker heating and avoid spurious breaker trips.

 

[mrau]

The Mobile Connector (UMC) that comes with the car will max out at 32 amps. So a 40 amp circuit & breaker for home charging will work out great.

 

[Gauss Guzzler]

I plan on installing a NEMA 6-50 with a 40a breaker since the wire is only 8/2 and I will be charging at 30amps.

It's safe for your particular use since the current generation of Tesla mobile connector can only draw 32A max which fits perfectly within the 80% rule for your 40A circuit, assuming it's copper of course.

But it's not legal because someone could plug in a higher power device and be driven so mad by the nuisance trips that they end up snapping and doing something stupid. Otherwise, the worst case scenario is the very small chance that an inspector might uncover your crime when you sell the house and force you to change the outlet and breaker to 30A versions.

 

[goldenstate01]

It's safe for your particular use since the current generation of Tesla mobile connector can only draw 32A max which fits perfectly within the 80% rule for your 40A circuit, assuming it's copper of course.

But it's not legal because someone could plug in a higher power device and be driven so mad by the nuisance trips that they end up snapping and doing something stupid. Otherwise, the worst case scenario is the very small chance that an inspector might uncover your crime when you sell the house and force you to change the outlet and breaker to 30A versions.

Electrician is coming out tomorrow to do it. It’s strictly going to be used for charging the Tesla and if I ever move out I’ll be sure to have it removed.

 

[wws]

You’re saying there are wires in the garage with no outlet and wires in the panel with no breaker ???

In a newly built house, it is a California Title 24 thing.

 

[davewill]

...
But it's not legal because someone could plug in a higher power device and be driven so mad by the nuisance trips that they end up snapping and doing something stupid. Otherwise, the worst case scenario is the very small chance that an inspector might uncover your crime when you sell the house and force you to change the outlet and breaker to 30A versions.

It's actually perfectly legal. Because there is no specific 40a NEMA outlet, you are allowed to use a 50a outlet on a 40a circuit. It's a very common installation in the rest of the EV world of largely 30a EVSEs.

 

[goldenstate01]

It's actually perfectly legal. Because there is no specific 40a NEMA outlet, you are allowed to use a 50a outlet on a 40a circuit. It's a very common installation in the rest of the EV world of largely 30a EVSEs.

Yes electrician just finished installing it! Thank you!