Nema 6-20

[Cottonwood]

You should be able to wire a 30 amp dryer receptacle and corresponding breaker to this. You might find that this is enough. I would charge at 25/24 amps with that setup.

I agree completely! See American wire gauge - Wikipedia. Even at the lowest insulation temperature, you can do 30 Amps with #10 copper. On top of that you have all 4 wires (two hots, neutral, and ground). Put in a NEMA 14-30R (Receptacle), change the breakers to 30 Amps (rating for wire and receptacle).

With this set up, when you get the 14-30 adapter from Tesla, the Mobile Connector will automatically set the correct current of 24 Amps, and you don't have any cheater cords. The 14-30 has enough stiffness that the Mobile Connecter will dangle from it nicely, and you have a good, clean, current-code-compliant installation.

Good Luck!

 

[strider]

Then, you can either use the L14-30 adapter for the UMC (if you want the correct solution), or you could buy an RV conversion cord and use the NEMA 14-50 plug that comes with the UMC:

Just a note that the UMC comes with the 120V plug and one adapter of your choice so you can choose any of the adapters here: Charging Model S | Tesla Motors Also I don't think the Tesla 14-30 is of the Locking variety.

 

[adelman]

Yes, the white is reserved for neutral. That's good news...

If you want to use the existing wiring, your best bet would be to replace that outlet with a NEMA L14-30 (twistlock), the kind that generators usually have on them. Then the only thing you have to do is replace the breaker with a 2-pole 30A breaker and make sure the neutral wire is hooked up in the panel to the neutral bus. You may have clearance problems in that box because a L14-30 receptacle is pretty big, but you can find some single-gang receptacles out there.

This would let you charge at 24A within spec... out-of-spec you could probably push up a bit.

I've used L6-30s extensively in EV charging since 1998 (built adapters from everything you might ever find to L6-30, L6-30 extension cords, and adapters from L6-30 to the car. I also have pile of burned up L6-30 plugs and receptacles from "pushing them" and can tell you that they are definitely not suitable for 30A continuous load (L14-30s have the same size/style blade) and this is in open-air. I'd be worried about using one mounted in a receptacle box even at 24A.

To change the subject: The Tesla 14-50 adapter does not use the neutral. A simple ohmmeter can confirm that the neutral pin on the adapter is not connected to the rest of the charge cable. With that in mind, "some people" have been known to hacksaw the neutral pin off the 14-50 adapter so it can be used in both 14-50 and 14-30 receptacles (it is also possible to remove about half of the blade so it fits in both style receptacles); you just need to be sure to set the current down in the car to a responsible level when charging off a 14-30. Now let's change it back...

You have a neutral and 30A wiring? Just install a 14-30 receptacle to code and if you want to cheat, do it outside of the receptacle by modifying your 14-50 adapter (and be sure to always set the current in the car down to 24A, but never over 30A).

You have the wire but not the neutral? Code would dictate the use of the 6-30 or 6-50 receptacle. If it's just temporary until your HPC arrives, "some people" might use a 14-30/50 and leave the neutral unconnected, but that WILL damage an appliance which expects the neutral to be there. "Some people" with modified adapters (cutting the neutral off), might just fill the neutral hole in the receptacle with a nice insulating glue of some sort to prevent its use by a different type of appliance. You definitely don't want to tie the neutral to the ground, as the ground conductor is undersized, and someone might plug in an appliance that sends enough current down the ground to start a fire in your wall.

But all of you are sane enough not to do any of this stuff, right?

 

[unclfuzzy]

I have a similar issue, except there is no outlet in the garage, but a heater wired to the 208/20 breaker. My Tesla rep said there are no other adapters available right now besides the 5-15, 14-50 and J1772. So I guess I'm going to have to have whatever receptacle meets code installed and get an adapter to allow me to plug in the 14-50, while dialing the car down to 16 amps. I don't know the wire gauge because it's in a metal jacket, but doubt it's any bigger gauge than was required for the heater since it was all put in when the house was built and it's a four story run from the box.

 

[sublimaze1]

So I guess I'm going to have to have whatever receptacle meets code installed and get an adapter to allow me to plug in the 14-50, while dialing the car down to 16 amps.

I guess I don't understand what you have posted here (meaning have to "dial down to 16"). If you have the space in the main, get a doubleD 50 amp breaker, 6-3 wire, NEMA 14-50 outlet (with a new-work box, plate, screws, etc.) and call an electrician. I assume the box is in the garage so your run can be short (the wire is the costly item here). I did this and installed a 14/50. I, too, have a welder plug in my garage which is a 208/220/16.9 amp outlet - but there are days/weekends when I plan to drive quite a few miles, and I do not want to short-change myself the charge time on a Sunday night after having gallivanted all over the metroplex for the weekend. The cost of the hardware was $129 and the electrician charged me $118 - so it was fairly cost-effective for me, IMHO.

WJ
P188
McKinney, Texas

 

[unclfuzzy]

The box is on the 4th floor. Main is in the garage. No existing conduit, given the construction, the cheapest way to get any other power there would be to replace the main cutoff and put in a sub panel for upwards of $2K. I rent, I commute 40 miles, and failing a way to make this work I'll charge with the 5-15. Breaker upstairs is two ganged 20s, just like Dave's pic. I just took a pic of a junction box on the way to that heater. Wire isn't labeled, but looks pretty thin. And there are only two wires. So those are both hot and the metal shielding is ground?

 

[FlasherZ]

I just took a pic of a junction box on the way to that heater. Wire isn't labeled, but looks pretty thin. And there are only two wires. So those are both hot and the metal shielding is ground?

The wire appears to be standard #12 based on the size of the wire and wire nuts. It also appears to be hot-hot-ground service (although I always wrap the white wires with black tape near the connectors when they're considered hot), a/k/a NEMA 6-style service. Unlike the OP, though, you don't appear to have #10 wire, so 20 amp is the max you can carry here.

But maybe I don't get what you're trying to do... is the car going to be plugged in on the 4th floor? Or are you going to break the circuit in the garage and use it? or co-opt the conduit (which is very small and won't host wire you need to get 30 or 40 amp service) for another circuit?

 

[unclfuzzy]

Car is going to be plugged in on the ground floor. Panel is on the 4th and I'm not going to invest in running new wire down from it. I talked to my electrician and he is going to install a 6-20 from those same pictured wires and make me an adapter for the NEMA 14-50 that comes with the Model S. I always assumed I'd just use the 110v outlet in the garage, so this will get me about double the charging rate of that for a couple hundred bucks. If it really turns out to not be sufficient for my daily needs I'll be using the J1772 at work until I decide to pony up for the $2K job at home.

 

[Cottonwood]

Car is going to be plugged in on the ground floor. Panel is on the 4th and I'm not going to invest in running new wire down from it. I talked to my electrician and he is going to install a 6-20 from those same pictured wires and make me an adapter for the NEMA 14-50 that comes with the Model S. I always assumed I'd just use the 110v outlet in the garage, so this will get me about double the charging rate of that for a couple hundred bucks. If it really turns out to not be sufficient for my daily needs I'll be using the J1772 at work until I decide to pony up for the $2K job at home.

I would suggest that you get a 6-50 plug adapter from Tesla with your car and have the electrician make a 6-20 to 6-50 adapter cable. Then there is no chance that anyone will ever misuse the adapter cable and create a hazardous situation.

 

[gdh66]

I like what Adelman states in post #43, "To change the subject: The Tesla 14-50 adapter does not use the neutral. A simple ohmmeter can confirm that the neutral pin on the adapter is not connected to the rest of the charge cable." because I plan to use Romex 6-2 (two hots and a ground) to wire a 14-50 receptacle for my Model S (cheaper, lighter, and easier to work with than 6-3). The code doesn't require a neutral for a 14-50R, and mine will terminate at the receptacle with 240v, no need for a 120v down the line. I'll check an adapter in our Tesla Store with a meter, but does anyone see anything wrong with this?

 

[strider]

Car is going to be plugged in on the ground floor. Panel is on the 4th and I'm not going to invest in running new wire down from it. I talked to my electrician and he is going to install a 6-20 from those same pictured wires and make me an adapter for the NEMA 14-50 that comes with the Model S. I always assumed I'd just use the 110v outlet in the garage, so this will get me about double the charging rate of that for a couple hundred bucks. If it really turns out to not be sufficient for my daily needs I'll be using the J1772 at work until I decide to pony up for the $2K job at home.

This sounds like a great plan. A 40-mile commute will only take a little over 3 hours to charge on 220/16A service vs 8 hours on 110V/12A service. Not sure what your sequence number is but Tesla may have a 6-50 adapter available by the time you're ready and if you use that then there's no issue on the unused neutral in the 14-50. 6-50 is hot-hot-ground just like the 6-20 you have. But you may want the 14-50 for road-trip stops at a campground.

 

[FlasherZ]

I plan to use Romex 6-2 (two hots and a ground) to wire a 14-50 receptacle for my Model S (cheaper, lighter, and easier to work with than 6-3). The code doesn't require a neutral for a 14-50R, and mine will terminate at the receptacle with 240v, no need for a 120v down the line. I'll check an adapter in our Tesla Store with a meter, but does anyone see anything wrong with this?

Yes. If you install a 14-50R, there is expected to be a neutral connected there, and anyone in the future who tries to use that receptacle for something else will wonder why it doesn't work. I'm not so sure that code doesn't require a neutral to be connected on a 14-50R, it's too late in the evening for me to dig through the book; even if it is a loophole, it will likely depend upon the AHJ and how strict they are.

If you're only going to run 6-2 with ground, why not just make it a 6-50 to be proper for a permanent install? Then you can use a small section of leftover 6-2 to make a 6-50P to 14-50R converter, and mark it accordingly. Then, if you get rid of the model S, you can always toss the cheater cable into the trash so it's not mis-used.

Typical rule of thumb for half-assing something electrically: if you're not going to do it right the first time (i.e., pulling 6/3 or using PVC/EMT with 3 individual AWG 6 conductors with a 14-50R, plus ground), at least connect the permanent portions properly, so that anyone who is inexperienced with your setup prima facie will not be surprised.

 

[FlasherZ]

I'm not so sure that code doesn't require a neutral to be connected on a 14-50R, it's too late in the evening for me to dig through the book

I posed this question on an electricians' board last night, got out my trusty NEC book this morning, and even asked the electrician this morning who was finishing up the install for my 14-50R in the garage (HPC to be installed later) of their opinions. While NEC sections 2 & 4 don't make mention of requirements to run the neutral, NEC section 110.3(B) states "All electrical equipment shall be installed and used in accordance with the listing requirements and manufacturer’s instructions." Since my 14-50R was installed this morning, I grabbed the small paper insert and looked it over; the wiring diagram shows that the neutral must be connected and does not leave it as optional. As a result, installing a NEMA 14-50R without a neutral wire will likely violate NEC 110.3(B). I suspect most, if not all, AHJ's would find fault during inspection.

 

[gdh66]

Thanks....Looks like I'll be using the neutral wire! Gracias to FlasherZ.

 

[chicagotsla]

Reviving this old thread.

I'm going to a hotel next week and would like to plug into the AC outlet (NEMA 6-20 240V, 20A). What is the easiest way to do this? Is there nothing "off the shelf" I can purchase to use as an adapter?

 

[Cosmacelf]

You'll have to make your own adapter, which is actually quite easy and (for me) fun to do. Check out this document, around page 10 it shows how to make a NEMA 6-20 adapter. http://cosmacelf.net/Home Made Adapters.pdf

 

[spaghetti]

Reviving this old thread.

I'm going to a hotel next week and would like to plug into the AC outlet (NEMA 6-20 240V, 20A). What is the easiest way to do this? Is there nothing "off the shelf" I can purchase to use as an adapter?

I was able to get a NEMA 6-20 plug to NEMA 14-50 receptacle adapter directly from EVSEadapters.com. Contact John Rowell at johnrowell at verizon dot net. Cost was $59 with free Priority Mail shipping included.

 

[chicagotsla]

Thanks guys, I used the following link: http://cosmacelf.net/Home Made Adapters.pdf , and had my warehouse guy make it for me. Hope it works. I'll remember to dial down the Amperage to 16.