Anyone use 10-50 plug to charge their Model S with Mobile Adapter?

Anyone use 10-50 plug to charge their Model S with Mobile Adapter?

I have built a few different adapters to convert to my NEMA 6-50 connector for my mobile adapter but haven't tried any of them yet. One outlet that is also 50 amps is the 10-50 outlet which was historically used for welders and such but does not have earth ground like 14-50 or 6-50 plugs do.

My question is has anyone actually tried using a 10-50 outlet to charge their Model S? I am assuming it will work and charge at 40A but wanted to make sure it would actually work as I plan to drive to my cabin about 150 miles away which has a 10-50 outlet in the garage. I can't really see how it could *not* work as there should be no way for the built in charger to actually detect that I am connected to neutral rather than ground but just checking.

I will eventually rewire this otulet to 6-50 or 14-50 so I have earth ground as well as neutral but that is a later project.

And just for clarity, my adapter connects the two line phases to the two line phases of the 6-50 connector and ties the neutral pole to the 6-50 ground wire.

I am just looking for actual experience to verify that it will work. I know I can just try it and am not looking for obvious common sense advice, just experience with this specific outlet configuration.

Brian H | November 22, 2012

Just try it. Heck, what could go wrong? ;) (Please give gory details!)

Sudre_ | November 22, 2012

It might not charge without an earth ground for voltage reference.

gimp_dad | November 22, 2012

Pretty sure it will work and I am going to try but was hoping to hear from someone who has tried it just to have the confidence that I can get home without needing days to charge on a standard outlet.

bsimoes | November 23, 2012

This could be a big deal if it doesn't work; I'd be calling Tesla on that one! Ask to be put in contact with the electrical engineering department.

JackB | November 24, 2012

It will probably work. Just adapted a 3-wire electric dryer outlet to a 14-50 outlet and the mobile charger did not mind the missing neutral wire.


Theresa | November 27, 2012

JackB, Did you mean the neutral wire or the ground wire? I realize in the implementation that you are doing it is really the same wire but I was wondering which leg of the 14-50 that you left disconnected. Or did you connect both ground and neutral together?

Michael S | November 27, 2012

I would stay away from home made adapters and extension cords. I made a couple for my Roadster and they would not work. The Roadster actually detected them and stated "extension cord detected" and would not charge with them.

Instead, I would suggest you bring a 14-50 outlet with you to your cabin and swap out the outlet like JackB did above. Just make sure the wiring and breaker are rated for 50 amps.

Scorch | November 27, 2012

Sorry to thread hi-jack but would any of you guys be willing to answer any of my questions on this? I really don't understand what magic goes on with the different outlet types, etc.

BYT | November 27, 2012

The Model S has both a unique and very advanced battery and charge system. Your Model S can detect and adjust to the line and current you feed it so as I understand it, if it fit's, it works with it.

ghillair | November 27, 2012

The following is copied from this link
Then select the adapter guide tab

Volts / Amps Kilowatts Miles of Range per
Hour of Charge
NEMA 5-15 Standard Outlet 110 V / 12 A 1.4 kW 5
NEMA 14-50 RVs and Campsites 240 V / 40 A 10 kW 31
NEMA 6-50 Welding Equipment 240 V / 40 A 10 kW 31
NEMA 10-30 Older Dryers 240 V / 24 A 5.8 kW 18
NEMA 14-30 Newer Dryers 240 V / 24 A 5.8 kW 18

It does say if installing a new outlet 14-50 is recommended.

Scorch | November 27, 2012

What if your outlet says 250V/50A? Is that still ok?

mrspaghetti | November 27, 2012


10 kW capable on-board charger with the following input compatibility: 85-265 V, 45-65 Hz, 1-40 A (Optional 20 kW capable Twin Chargers increases input compatibility to 80 A)

So yes, it's ok

Alex K | November 27, 2012

@Scorch | NOVEMBER 27, 2012: What if your outlet says 250V/50A? Is that still ok?

That is just the maximum capacity rating of the outlet. The actual capacity is determined by your wiring and your circuit breaker. The circuit breaker should be 50A, but the current draw is usually 80% of the maximum rated capacity (or 40A). If you have a NEMA 14-50 or NEMA 6-50 outlet the car will draw the appropriate amount of power that it needs. So in other words, a 250V/50A rated outlet is fine.

Scorch | November 27, 2012

@Alex Thank you so much! Hopefully I am good to go then. :)

goldfishapt | October 27, 2015

The NEMA 15-50 is a four socket receptacle. To wire it by code you need 6/3 AWG wire (three conductors plus a ground - hot, hot, neutral and ground). When wired like this it will provide both 120V and 240V. The Tesla only uses 240 so it does not need the neutral. You can get away with using 6/2 AWG (two conductors plus a ground - hot, hot and ground. This will be safe because ground is included, but it will not be to code.
I am wired this way because I'm a DIY and 125' of 6/2 is $150 and 125'of 6/3 is $250.
Not sure why Tesla chose the 15-50 receptacle when they don't need a neutral......

Rocky_H | October 27, 2015

@goldfishapt, It's 14-50, by the way.

"Not sure why Tesla chose the 15-50 receptacle when they don't need a neutral......"

That's because of availability of outlets, I'm pretty sure. There are many hundreds of RV parks and campgrounds where you can use that same adapter to charge the Tesla away from home at a pretty good rate. It was a pretty savvy plan, I think.

rswerts | October 27, 2015

@goldfishapt The NEMA 14-50 is common in residential installations as well as campgrounds, while the 6-50 is not as common.

The ground is required for Tesla charging(will not work without it) and the neutral is not. A neutral wire connects to the same place on the distribution panel as a ground wire, but a different pin on the 14-50 receptacle.

hpjtv | October 27, 2015

I think it also won't charge if line/hot and neutral are reversed or if there's no ground for the 5-15 120V adapter. I've ran into this situation once.