Bag of Spare Adapters?

TM now has several adapters for sale. Is there much benefit to buying some or all of them to have on hand when out on the road?

The ones I really wanted - NEMA 10-30 and 14-30 Dryer plugs - aren't available so I made my own. Other than that, 5-15, 14-50 and J1772 should be the ones you need, and they come with the car.

I'm thinking it would be a good idea to have them "all" whenever away from my home by 100 miles or outside the real world range of the car to reach my garage again.

Seemingly it would be to ones advantage to have as many options as possible when on the road.

nickjhowe | FEBRUARY 16, 2013 NEW
The ones I really wanted - NEMA 10-30 and 14-30 Dryer plugs - aren't available so I made my own. Other than that, 5-15, 14-50 and J1772 should be the ones you need, and they come with the car.

Nick, how did you make your own adapters? I am interested in the two dryer outlets too but I can't find them anywhere.

I need to connect to an older low power RV outlet which is a NEMA TT-30 (120v 30A). Someone suggested using this adapter found on Amazon

but to be sure to dial the amps down to 24A. I wonder if anyone else has tried somethin like this.

Nick is very talented and he covered this topic extensively in prior posts. He even posted pictures. He has deep knowledge of electricity, outlets, tools, etc. I spent a couple of hours searching for ready-made adapters on Ebay and Amazon and gave up. Tesla will supply them when they get around to it. They are available for Roadsters.

The 14-50 to TT-30 does not work. I just tried it today as a test. The TT-30 is 120 volt. The 14-50 is 240volt. I bought it for $14 at an RV store. My real plan is to turn it into a 14-50 to 6-50 adapter.

You could get an adapter for 120 volt plug that comes with the car but you would be limited to 12 amps on a 30amp source and that would suck.

@Sudre - when you say it doesn't work, what is the problem? The Mobile Connector supports 120V and doesn't care what connector it comes in, as people have succesfully made 20A@120V adapters that use the 14-50 adapter - the car shows 120V, and you dial the current down to 16A.

@nvjx - making a 14-30 adapter is easy, and if you don't mind modifying the adapter (now that you can buy a spare it is less of an issue) you can simply cut off the neutral pin as the other pins are exactly the same between 14-30 and 14-50 (and the Mobile Connector only cares about the two hots and ground). 10-30 is trickier because it doesn't have neutral but has ground, so you have to do something which is unsafe in general but happens to work in this specific case, which is to tie ground on the 14-50 receptacle, only to be used by the Tesla, to neutral on the 10-30 plug. You could also make an adapter that has 10-30 and a regular 15A@120V plug, and use the 120V plug only for ground, but you would have to always have both plugs plugged in before hooking up the car. Neither of these are hard, but if you aren't sure what you are doing don't do it.

This has been discussed in detail in several threads already.

So if I take 35 Walmart extension cords, strip off the insulation, wrap in aluminum foil, tie with paper clip and then jam it all into the charging port with a penny I should be okay right? ;)

It will definitely carry current. How long, and where, is hard to say. <;)


Any chance you want to post how you made your own, or sell me one? :)

I have read countless threads on this subject and you seem to be the SME (subject matter expert). Instead of trying to make my own, I could just pay you a profit to make one for me and send it to me?

I know its a stretch but I figure it wouldnt hurt to ask. Only 240 in the place is a NEMA 10-30 receptacle.

I would definitely carry as many adapters as I could make or buy. Pretty much wherever you go, if you stop somewhere out in the middle of nowhere, they probably have electricity, and probably even have 240 Volt of some sort available... but if you can't connect, that's a problem.

Can somebody knowledgeable post 1) a list of the common AND uncommon 240 V plug types; and 2) a wiki on how to make adapters for such plugs?

I may have to do some independent research.
Yes, eventually an expensive adapter list will be available from Tesla. I want mine now. :)

@cloroxbb - personally I am not willing to do it, because it is definitely not something that would pass code (tying neutral to ground in the adapter). I'm willing to do it for myself and describe it, but if there is a problem and it burns your house down or somebody gets shocked, I don't want to be held responsible for it.

@Logical_Thinker - you can look at the Roadster adapters for the variety that would make sense. Making most of them is really simple - you get a 14-50 receptacle, a metal box and cover, a plug that matches what you want, and then wire them up with appropriate wire (I would go with #6 copper to overdesign it if the plug doesn't come with a cable, such as dryer plug). You just match hot to hot (which one doesn't matter), ground to ground, neutral to neutral. In the case of a 120V source, you wire hot and neutral to the two hots in the 14-50 adapter. If the source doesn't have neutral or is 120V, then you just leave neutral unconnected on the 14-50. Do not leave ground unconnected on the 14-50 -- the car requires it and it is dangerous to leave it unconnected anyway. Make sure the receptacle connects ground to the metal box, and if not run your own pigtail to it. Note that I personally haven't made any 120V adapters, but other people have reported that the Mobile Connector is happy with 120V (one person has reported lack of success, but didn't say exactly what). When you hook it up, be sure and dial down the charging current to 80% (due to continuous load derating) of whatever the outlet is rated for, since the car thinks the 14-50 adapter is connected to a 50A circuit and will automatically charge at 40A if you don't tell it otherwise.

Again, don't attempt any of this if you don't know what your are doing. You can potentially shock someone or burn down your house if you do it wrong.

The TESLA site doesn't show the receptacle ends of the adapters. My solution: Search for "RV Adapters" on Google or Bing. I found an 18 inch, 30A to 50A adapter on several sites. I also found them at a local home improvement store. The 30A plug appears to be similar to a NEMA 5-30 with a round neutral/ground pin instead of the NEMA L-shape. The 50A receptacle is NEMA 14-50. Delivery of our car is not expected until May-June. Before then, I plan to buy three of these and replace the plugs on two of them with NEMA 14-30 and 10-30, respectively. Any one of them will connect to the NEMA 14-50 adapter that is furnished with the car. I haven't decided yet whether to build or buy a 50A extension cord. Dryers and RV campgrounds here we come.


I definitely understand. Thanks anyway. I could probably make my own, I just need a wiring diagram.

I would not bother following jat's descriptions. While they will work at home without a GFI and he does mention the unsafe bits which is acceptable to some. The only reason you really need these adapters is for traveling. At home just buy a 14-50 outlet which is cheaper than making adapters. Almost ALL RV parks have everything on GFIs. If you are connecting neutrals to grounds you will trip the GFI and the rigged adapter is useless.

I would not recommend using these rigged adapter in corporate or public parking garages. The last few places I worked at the insurance companies are forcing the places to use GFI main breakers at their switch gear. We were doing a job in a BJC parking garage and a 208 volt saw was used to cut the floor. The workers didn't want to pay for a temp outlet so they rigged an adapter similar to what jat describes. They tripped the GFI on the main breaker to the building and the whole garage lost power. They were thrown off the job by the customer. We do not want to give Tesla a bad name.

As far as the store bought tt-30/14-50 adapter not working.... I bought the adapter over the counter. I plugged it in. It had a neutral, ground, 120volt from A to neutral, 120volt from B to neutral, nothing between A and B phase (because they are same phase). I guess the Tesla box knew something was wrong because it would not work. The car said no power. I am guessing because I had no voltage between A and B even tho I had voltage between ((A or B) and the (neutral or ground)). I will play with it because I think it can easily and safely be edited to work but I just haven't had time.

If you are not familiar with electricity and phasing or what I or jat means by A and B phase then do not make these adapters. Jat sound like he knows what he is doing. There is a reason why he won't make one for you. He would be liable so why would you make one for yourself. Your insurance company will not pay for you burning down your house with a rigged adapter. You will be S.O.L. If an inspector find you plugging in a NON-UL listed adapter you will be in trouble. I imagine a park ranger will throw you out on the park.... altho I doubt they'd even look.

Last bit. If jat does not understand why the over the counter tt-30/14-50 adapter didn't work it means he has not fully tested all his theories. Maybe Tesla has added in some safeties to prevent some of these adapters.

Oh and I did buy a 15' 6 gauge 14-50 extension cord. I am glad I did. The first campground I charged at the plug was 30' away. I didn't want to drive across the grass.

So when will 10+ adapters be available from Tesla? I really don't mind plunking down even a bit more than the $800 (for the Roadster) if that means that at some random place out in the middle of nowhere I'd be able to use their plug

@cloroxbb - I thought about offering to make some, but was concerned for the same reasons as @Jat. Although a 10-30 to 14-50 adapter works, it is dangerous in the hands of the unwary/uneducated and I don't want to be on the wrong end of a lawsuit.

Again - I'm not an electrician so what I'm posting here is what I've picked up as I've gone through this process myself. The diagram below is my best understanding of things. Click on it for the full size image. I'm sure @Jat or or one of the other knowledgeable folks will jump in and point out any flaws. Since there's no edit on this forum if I make a mistake in this post it is going to be difficult to fix it.

Here we go...NEMA 10-30, 14-30 and 14-50

The 10 or 14 refers to the type of connector; 30 or 50 is the rating in Amps.

'14' is a four wire connector: ground, neutral and two hot wires that take the two different 120V phases in your house. From neutral (W) to hot (X or Y) is 120V, but hot-hot (X to Y) is 240V. This is NOT the same as a European 3 phase supply. On the US split-phase system the two phases are 180° apart so the difference between the two sine waves is 240V. (you can get as much as 250V, depending on the feed)

The neutral pin in the '14' connector is there so that you can draw 120V if you want to.

Connecting a 14-30 plug to a 14-50 receptacle is easy because the wires are the same; the only thing you need to be careful of is that the Model S 40A pull will override the 30A breaker - so you need to dial the current back (to the 24A continuous load that is required for a 30A circuit)

'10' is only a 3 wire connector, neutral and two hots. Connecting a 10-30 to a 14-50 has the problems above, plus the MAJOR problem that the 10-30 requires a neutral, but the Tesla 14-50 connector REQUIRES a ground for it to work.


The solution is to wire (Home Depot has 6/4 and 6/3 SOOW cable by the foot) the neutral in the 10-30 to the ground in the 14-50 and leave the 14-50 neutral unconnected. Or connect both the neutral and the ground in the 14-50 to the neutral in the 10-30. BOTH OF THESE ARE VERY BAD. If something were to go wrong there is a risk of electric shock/burning your house down. And 240V can definitely ruin your day. As can burning your house down.

Here's the diagram:

Uploaded with

I would definitely carry as many adapters as I could make or buy. Pretty much wherever you go, if you stop somewhere out in the middle of nowhere, they probably have electricity, and probably even have 240 Volt of some sort available... but if you can't connect, that's a problem.

Can somebody knowledgeable post 1) a list of the common AND uncommon 240 V plug types; and 2) a wiki on how to make adapters for such plugs?

I may have to do some independent research.
Yes, eventually an expensive adapter list will be available from Tesla. I want mine now. :)

I did a little testing between the TT-30 to 14-50 adapter I bought at an RV store and I know why it doesn't work. Tesla's has done things specifically so these adapters will not work.... or at least the one I bought will not work. For those that might understand read on.

The TT-30 to 14-50 adapter I have takes the:
ground to the ground
Neutral to the Neutral
TT-30 A phase to the 14-50 A and B phase

The Tesla 120 volt head does not do that. It take:
ground to ground
Neutral to B phase *
Hot to A phase *
If the hot and neutral are reversed between the A and the B it will show a red light.
If A and B on the Tesla 14-50 have the same 120volt phase on them it will just not work at all.

It will be easy to make adapters that do not require crossing over anything by just going to your local hardware store and buying the correct cord ends and the correct gauge wire as needed.

I would not recommend this for a novice.

I would rather purchase the Tesla product than create BUT there are several campgrounds in MO and IL that only have TT-30 outlets and I don't see it as an option in the Tesla store... so I will make one. My wife is already planning to go camping this spring in a campground that only has TT-30 outlets.

* I might have these reversed.

@Logical - maybe our posts crossed.

One thing I forgot to mention - there is a TT-30p to 14-50r pigtail available on Amazon. Do not buy it unless that is exactly what you want. Only one of the hot legs on the 14-50 is wired so will only deliver 120V, NOT 240! And both plugs are molded, so can't be taken apart and rewired. (I know, I tried)

CHadeMo Adapter. Anyone know of an adapter for the CHadeMo quick charge system ? Can't find one for my Model S on the Tesla site.

A TT-30 is only 120 volt 30 amp to start with. That adapter on amazon won't work anyway as I tried to explain above.

@nickjhowe - one minor correction -- the 240V plugs can vary anywhere from 208V to 250V. It will be 220V-250V if they are both phases of a split phase source, and they will be around 208V if they are two legs out of a wye or delta-wired 3-phase system.

@mallynb - the Roadster page I was talking about is at and does show pin diagrams.

@Sudre - none of this was intended for use at your house, but instead when you are travelling. A friend I am visiting is very likely to have a dryer outlet, but they are far less likely to have an RV outlet. A 120V GFI breaker measures the current flowing back on the neutral and if it isn't the same as the current going out the hot line then it opens because there must be leakage to ground somewhere. 240V GFIs are similar, but have to measure across both hots and the neutral. In any case, it shouldn't be any different, as the car shouldn't be leaking any current to ground anyway and if it does you definitely do want the breaker to trip as the car chassis will be unsafe.

When you say the B phase has to be the grounded conductor when using 120V, which one does that correspond to on the 14-50 adapter?

I would love to install a 14-50 but I live in a duplex, so Im going to have to see if I would be allowed first. There is already a dryer outlet (10-30), but from the looks of things, I should probably not risk it.


Thank you very much for the info, my LAST question is:
Are you using a home built NEMA 14-50 to 10-30 adapter and how has it worked out for you?

Thank you for your input as well.

@cloroxbb - I do have a home built adapter. Fortunately I also have a 14-50 that I put in, so don't need to use the 10-30, but I did test it (my dryer is 10-30) and it worked fine when I dialed the current back to 24A. The prongs on the 10-30 plug got a little warm, but other than that it worked great. I also built a 14-30 adapter for use at my mother-in-law's.

I am going to have my electrician make a 30 foot extension cord to go from nema 15-50 to nema 15-30 as every family member and friend I know has a dryer plug within 20 feet of their garage. That will allow me to drive everywhere and fully charge overnight.

jat my only concern is putting the neutral and the ground together. That is when the gfi can trip because some of the current returns on the ground path. Looks like there should never be a need to do that.
A and B. . .14-50 . . . When I get home I will let you know. I wrote it on the 14-50 plug which is hanging in the garage.
Has anyone found a pretty 14-50 female cord cap/plug? I don't want to use a box and outlet for my TT-30 adaptor. Guess I could buy a short 14-50 extension cord and cut the male end off. . . it just hurts saying that.

Looking at the prices of some of the cord caps it is cheaper or about the same price to buy Telsa made adapters. . . if they have them.

@dstiavnicky - was there a typo - did you mean 14-50 to 10-30? I'm not familiar with a '15' type NEMA connector.

@cloroxbb - I have made a 10-30 adapter and the Mobile Connector is happy with it, but I haven't actually charged my car with it yet (my dryer plug is on the opposite side of the house from the garage).

@Sudre - I saw some pigtail cords that had a molded 14-50 receptacle, but they cost a lot more than just buying a metal box and an outlet, so I went that route. This is only temporary until Tesla sells the adapters anyway (for me at least). I agree that if the car used neutral at all then it would be a problem to tie neutral/ground in the adapter, but it isn't even connected.

@dstiavnicky - assuming you meant 14-30 to 14-50, note that any older houses are likely to have 10-30 instead (our house is 37 years old but the entire electrical system was upgraded about 15 years ago, and it still has a 10-30 dryer plug.