NEMA 14-50 to Standard 3 prong outlet?

[Rocky_H]

Helpful post, my situation is different. I have electric dryer outlet in my garage with two 120s and a neutral (assumed), I want to replace that outlet with 14-50 for my M3. Can I hook up that third wire to ground in the new outlet? I am not sure if it is grounded or not at the panel but according to these posts all homes prior to 1996 (mine built 1993) were grounding the neutral.

Make sure you know what it really is. This may help you identify it. There's a chart on the side that shows most of the common types. Three prong dryer outlet is most likely a 10-30.
NEMA connector - Wikipedia

First question: since it's in your garage, so probably close enough, why not just order the 10-30 plug adapter from Tesla and use your real Tesla charging cord with it? That is easiest, most obviously correct, most foolproof, etc than trying to change your wiring. But I'm already concerned by your mentioning of a 20A breaker. That wouldn't be right for a 10-30 outlet (that second number says how many amps it's supposed to be for), so I would worry a lot about just plugging in and using it as-is. You probably should have that looked at before using it.

Other than that, there may be possibilities of changing the outlet to something else, depending on what the wire size is or other things, but that's more detailed than I would want to recommend or explain for this kind of situation over the internet. Have an electrician look at it, and see what you can come up with.

 

[fazluke]

Make sure you know what it really is. This may help you identify it. There's a chart on the side that shows most of the common types. Three prong dryer outlet is most likely a 10-30.
NEMA connector - Wikipedia

First question: since it's in your garage, so probably close enough, why not just order the 10-30 plug adapter from Tesla and use your real Tesla charging cord with it? That is easiest, most obviously correct, most foolproof, etc than trying to change your wiring. But I'm already concerned by your mentioning of a 20A breaker. That wouldn't be right for a 10-30 outlet (that second number says how many amps it's supposed to be for), so I would worry a lot about just plugging in and using it as-is. You probably should have that looked at before using it.

Other than that, there may be possibilities of changing the outlet to something else, depending on what the wire size is or other things, but that's more detailed than I would want to recommend or explain for this kind of situation over the internet. Have an electrician look at it, and see what you can come up with.

I already called an electrician, For clarifications, I have two 20 amps linked together at the panel and I checked the wires at the outlet and there are two blacks and one white and the current outlet is NEMA 10-30. Since delivery is tomorrow, I'll buy the 10-30 adapter and use it till I make the upgrade (if needed - 22 mile / hr might be good enough for my needs)

 

[csanders90D]

Whoever wired that outlet did it wrong. You're not allowed to put a 10-30 output on a 20 amp breaker. If you plug in your car with a 10-30 adapter, it will pull 24 amps from EACH of those black wires. Best case you will pop a breaker, possibly burning or melting things in the process.

Your options are:
* Replace with outlet with a 6-20, leaving the wiring and breakers the same. Tesla makes an adapter for this, and you'd charge around 15 mph. This is the cheapest option, if 15 mph charging is enough.
* If the wires are large enough gauge (unlikely), you could increase the breakers to 30 amps and use a 10-30 adapter.
* Re-wire the whole thing with larger wires, breakers, etc. This is most expensive, but will give the best charging rate. This also gives the peace of mind of getting rid of the shady work of the original electrician.

Car charging is probably the largest electrical load in your house, which will run for many hours continuously, while you're asleep. Don't risk burning your house down over a couple dollars.

 

[Rocky_H]

I already called an electrician, For clarifications, I have two 20 amps linked together at the panel and I checked the wires at the outlet and there are two blacks and one white and the current outlet is NEMA 10-30. Since delivery is tomorrow, I'll buy the 10-30 adapter and use it till I make the upgrade (if needed - 22 mile / hr might be good enough for my needs)

WOW!! Yeah, @csanders90D got to it first, but I want to concur and emphasize. DON'T plug a 10-30 into that outlet!!! That is a wrong, undersized breaker for that outlet. Yes, you can turn down the amps in the car, but if you read that here, but then forget to actually do it when you plug in, it's bad.

Replace with outlet with a 6-20, leaving the wiring and breakers the same. Tesla makes an adapter for this, and you'd charge around 15 mph. This is the cheapest option, if 15 mph charging is enough.

Yes, that is a good option.

 

[fazluke]

WOW!! Yeah, @csanders90D got to it first, but I want to concur and emphasize. DON'T plug a 10-30 into that outlet!!! That is a wrong, undersized breaker for that outlet. Yes, you can turn down the amps in the car, but if you read that here, but then forget to actually do it when you plug in, it's bad.


Yes, that is a good option.

Thank you'l for the advice and recommendations, a little knowledge could be fatal. An electrician installed a 14-50 for me and that one I was thinking about was limited to 20 amp (Dryer's). Cost was $350, always seek professional help.

 

[Rocky_H]

Thank you'l for the advice and recommendations, a little knowledge could be fatal. An electrician installed a 14-50 for me and that one I was thinking about was limited to 20 amp (Dryer's). Cost was $350, always seek professional help.

I am really glad you looked at that. It amazes me sometimes what people end up with. I went over to a friend's house who was planning to get a Nissan Leaf to see what he had and what kinds of options would be available for charging. He had mentioned he had "a 220 outlet" already from an air compressor he used to have that he didn't use anymore. (Side note: I see that from a lot of people, where they don't know that there is more than one kind of 240V outlet.) I went to take a look at it, snapped a picture and saw that it was a 6-50 outlet, and I thought, "Oh, good, he'll be pretty well set up." But then we looked back in his panel to see what it was hooked up to, and it was a 20A breaker!!! What the hell? How did anyone think that was OK? I told him that was not OK at all, but if he wanted to use that circuit, he HAD to get rid of that 6-50 outlet, and he could get a real Clipper Creek EVSE made for a 20A circuit.

 

[n2mb_racing]

I am really glad you looked at that. It amazes me sometimes what people end up with. I went over to a friend's house who was planning to get a Nissan Leaf to see what he had and what kinds of options would be available for charging. He had mentioned he had "a 220 outlet" already from an air compressor he used to have that he didn't use anymore. (Side note: I see that from a lot of people, where they don't know that there is more than one kind of 240V outlet.) I went to take a look at it, snapped a picture and saw that it was a 6-50 outlet, and I thought, "Oh, good, he'll be pretty well set up." But then we looked back in his panel to see what it was hooked up to, and it was a 20A breaker!!! What the hell? How did anyone think that was OK? I told him that was not OK at all, but if he wanted to use that circuit, he HAD to get rid of that 6-50 outlet, and he could get a real Clipper Creek EVSE made for a 20A circuit.

Or a NEMA 6-20 outlet!

The under appreciated 20a, 240v option!

 

[Rocky_H]

Or a NEMA 6-20 outlet!

The under appreciated 20a, 240v option!

Sure, to replace just the outlet for general purposes, but this was to charge a Leaf, and that has nothing that can plug into a 6-20. It just comes with that crummy little cord that can only use 5-15 or 5-20 outlets. So rather than having him replace the outlet AND spend a few hundred dollars on some kind of portable EVSE that could plug into that, it was more straightforward to just recommend a hardwired 20A EVSE.