Model 3

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Will not charge on 30 amp RV plug

edited November -1 in Model 3
Just got my M3 Black EAP 19" on Sunday. Was a big surprise since my delivery agent said mid next week and he would check with logistics... Not complain and grateful and glad I was home to accept.

So charging I have a 30 amp RV type plug on the outside of my house that runs my rv when I have it home to pack ( ac running ). So i know it works. I used the 30 amp to 50 cord from my rv to plug in my M3. Nothing... No Lights Car says ready to charge. So I swap to a 110 circuit and lights and car see power. So I buy a new 30 ==> 50 converter and this one has a light to show power. Nothing again on Tesla Charger and car says ready to charge. I am going to run a state park over the next couple of days and try their circuit but what am I missing? Car charged today at public EV station using J-1772 converter at 30 amp 15 mile / hr.



  • edited September 2018
    You need a special third party TT-30 adapter to charge. Your RV 30amp is 120v at 30 amps, not 240v 30 amp. The wiring is slightly different.

    A few people make them.... Here is a link to one:

    btw. EVSEAdapters somewhere on the site says you will charge at something like 8 miles per hour with it.
  • edited September 2018
    Agree--the 120V makes this a trickier charge, but it is possible with the proper configuration.
  • edited September 2018

    Assuming you have the mobile connector, then it is recommended that you charge using one of the solutions described at this link:

    For a 30 amp outlet, you need a NEMA 14-30 outlet and adapter. If your RV plug is a TT-30, that is not what you need if you want to use Tesla's adapters.

    It has been reported that the NEMA 10-30 has been discontinued.

    Until you get a proper higher amperage outlet, charge with your 120 AC adapter using the mobile connector that came with your car. If you have a new outlet installed, have a NEMA 14-30 installed or better yet a NEMA 14-50 put in if you can support it (or else have a Tesla wall connector installed).
  • edited September 2018
    Thank you. I am guessing on the 30 amp twist lock in the marine industry will require a special adapter as well? I am just wanting to cover all my bases.
  • edited September 2018
    The outlet end of an "RV 30a to 50a adapter" looks just like like an NMEA 14-50R outlet, but it's not wired the same way. It's a very special adapter and cannot be used for anything other than an RV.

    Large RVs that plug into a 240v/50a NMEA 14-50R outlet rarely use the 240v that is available across the two hot legs of a normal NMEA 14-50R. Instead, they treat each leg of the 14-50R outlet as a separate, isolated, 120v circuit. This allows them to spread the load across two circuits.

    An "RV 30a plug to 50a adapter" takes the 120v/30a from an NMEA TT-30R outlet and connects that to BOTH legs of what looks like an NMEA 14-50R outlet. That provides 120v from each leg to neutral, but ZERO volts between the two hot legs because they are IN PHASE! It's a cute trick that works for many RVs, but it's totally useless for any other purpose - including EV charging.

    Fortunately, our Teslas' are voltage-agnostic - they don't really care if the voltage supplied is 240v or 120v - they roll with anything. And, there is at least one "TT-30 Adapter for Tesla Model S/X/3 Gen 2" available that is wired for our Teslas (search for the text between the quotes and you'll find it). I haven't yet tried it, but it is alleged to work.

    There are other (cheaper) TT-30 to NMEA 14-50 EV charging adapters that supply 120v across the two hot legs of the 14-50R outlet. That might work for our Teslas, but it could be dangerous if someone tried to use it with an RV (and those adapters look exactly like the RV adapter).

    Caveat emptor!
  • edited September 2018
    Folks are correct that camping supplies wire things in an entirely different way, so those "dogbone" kinds of RV adapter cables from TT-30 to 14-50 will never work for charging an electric car. I know there are a lot of old timers that are trying to be helpful, directing you to aftermarket TT-30 to 14-50 adapters for electric cars, but those require manually dialing down the current in the car, which you might forget, etc. etc. That is what we had to do 2 or 3 years ago, but EVSEAdapters was finally able to make real adapters for the 2nd generation Tesla mobile charge cable that just handle this directly.

    So @kevin_rf has the right answer:
    It's $75, which I know, seems a little pricey, but it is the right thing to get. It will automagically set the current to the allowed 24A from a 30A circuit without you needing to remember or do anything.
  • edited September 2018
    My TT-30 came with a big sticker on it saying to dial down the amps in the car before using. $45 on Amazon - maybe not worth the savings, but the EV adapters one is now discontinued.
  • edited September 2018
    I'd rather dial down the amps and retire early, but that's me.
  • edited September 2018
    @SION1771 Is it discontinued, or as EVSEAdapters lists, temporarily out of stock?
  • edited September 2018
    @kevin_rf - sorry... I shouldn't pretend I know. I've read different stories on their situation so I'm not sure and assumed the worst.
  • edited September 2018
    al, I would underscore what kevin_rf and Rocky said and go for the ESEAdapter.. if they come back in stock. You can also follow BigHorns' advice, but you must be a naturally careful person and remember to be sure the charge rate is manually lowered (or the car will try and draw too much current).

    I have corresponded with the owner of EVSEAdapters in the past. I might just shoot him an email and see whats up with that TT adapter.

  • edited September 2018
    BTW, EVSEAdapters is suggesting an alternate adapter until the "temporarily" out of stock Tesla adapter is in stock again. Unlike the out-of-stock adapter the substitute does NOT properly inform the car what outlet it is connected to, and the car will try and draw too much current! (unless you have manually dialed it back from the console).
  • edited September 2018
    If you set a current limit, it becomes geofenced forever. How many individual TT-30 or marine locations do you suspect someone will be using?
  • edited September 2018
    "forever" defined as "until it isn't"
  • edited September 2018
    BH, that was a nice little PDF you linked to. I like the actual photos of the outlets. Have you ever heard of someone installing a 14-60 in their garage?
  • edited September 2018
    Also if dialing back the current level isn't something you normally have to do at your normal TT-30 charging location (because you set it once a long time ago) you might easily not remember to do it at a new TT-30 location and then wonder why the car is tripping the breaker (or worse).

    I agree getting the right adapter that always just does the right thing automatically it worth the extra expense.
  • edited September 2018
    I’ve not come across a 14-60.
  • edited September 2018
    If you have a fire using non Tesla adaptors, you may have a hard time getting your insurance company to cover.
    It would be a lot better to get an electrician and have proper wiring installed.
  • edited September 2018
    @Atoms, the evseadapters unit is also non-Tesla; there isn't a Tesla designed TT-30 option.
  • Will this not work? It’s from Tesla and half the price:

    I am running into the same issue. Would appreciate clarification. Thanks.
  • @hubharani_98221572: Welcome to the forums!
    First, there was quite a bit of discussion in this thread about a multiplicity of different adapters. So, exactly what socket have you got? If you're not sure, take a picture of it, put the picture up on, I dunno, Twitter or some photo place like Flikr or Google Photos where you can share a link, and post the link here. Then we cognoscenti will tell you what you need to do.
    Should mention, though: The Gold Standard for sockets has 240 VAC and 40A, the NEMA14-50 being somewhat favored over the various others.
    Good luck!
  • Thanks. Sorry for not being clear. I was referring to the 30 Amp outlet in the RV park.

    Tesla seems to be making the 14-30 and 10-30 adopters please see here:

    Please select 10-30 in the drop down in this link above. Which matches the 30 Amp adapter in the Arab park.

    Will that not work for charging my Tesla in the RV park’s 30 Amp outlet? This one Costa $35 v/s the EVSE $75 adopter.
  • So, my go-to chart of these things is at
    NEMA14-30 is a four-wire connector with GND, NEUTRAL, and two hots, each 120 VAC to Neutral, and, being 180 degrees out of phase with each other, 240 VAC across the hots.
    NEMA10-30 is a 240 VAC with three pins: One neutral, two hots, and the two hots are (presumably) 240 VAC from each other.
    Both of them have a nominal maximum current of 30A; the Tesla, when hooked to either, will draw a maximum of 80% of that, or 24A. 240Vx24A = 5760W. Given that a M3 gets around 250 W-hr/mile, either will give you a charge rate of around 23 Miles of Charge per Hour.
    So: If it really is a NEMA10-30 at the RV park, then the Tesla Mobile Connector and the 10-30 adapter will get you where you need to be.

    But, be careful: If you look at that Wikipedia chart, you'll notice that there's listed for RV/Trailers a NEMA TT-30. Yes, the socket does have the slanty blades which kinda look like the NEMA 10-30, but that's not what it is: the connector has three pins, GROUND, NEUTRAL, and HOT, and the HOT is 120 VAC @ 30A to the Neutral, which is _not_ what a NEMA10-30 is. The NEMA10-30 is a 240 VAC connector, the NEMA TT-30 is at 120 VAC, very definitely not the same thing. A closer look at that chart shows that the Neutral on the NEMA10-30 is a little right-angle thingy; the GND on the NEMA TT-30 is a half-round, about the same size. You might be able to force things, but I foresee letting the smoke out if you do.

    Just kind of curious. I'm not overly familiar with trailer parks and their electrical connections. Does the one you're interested in have other connectors than (I think) NEMA TT-30?
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