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14-50 installed on 30-amp breaker

Discussion in 'Model S: Battery & Charging' started by 8lincoln30, Mar 26, 2017.

  1. 8lincoln30

    8lincoln30 Member

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    I did copious amounts of research and decided I could install my Tesla charging infrastructure myself, connected to a subpanel in my garage.

    I bought a remanufactured meter online and installed it between the subpanel and the 14-50 outlet. It works like a charm (see pic).

    Here's the rub: my subpanel is connected to a 30-amp breaker at the main panel. I considered replacing that with a 50-amp breaker but realized I'd need to rewire the run from main to sub. That is above my comfort level, or at a minimum far more effort than I'm willing to do myself.

    So I installed another 30-amp breaker in the sub, and connected that to the 14-50. I limit the Tesla to 24 amps.

    I realize this may not be entirely up to code, but I'm certain there are no safety or reliability issues. I live alone and no one else has access to the garage. If I were to sell my house, I'd remove the whole setup first.

    I'm posting this because this is a sub-$100 solution to a problem people are paying $1,000 to solve. I think people should know that it's not all that difficult if you adhere to common sense regarding the maximum amps you'll draw from the 14-50.

    Now, feel free to pillory me for my recklessness and disregard for authority ... or suggest improvements ...
     

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  2. DarkMatter

    DarkMatter Member

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    I would install a 14-30 instead now that the correct adapter is available:

    Tesla — NEMA 14-30

    Then your install will be to code without the expense of the Wall Connector.
     
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  3. 8lincoln30

    8lincoln30 Member

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    Well, I'll be damned ... when did that become available? Must have been the past few weeks. I'll do that ASAP.
     
  4. Petra

    Petra Member

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    Tesla has offered 14-30 and 10-30 adapters on and off for several years. The 14-30s recently came back likely due to the recall.
     
  5. TexasEV

    TexasEV Well-Known Member

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    I disagree when you say you're certain there are no safety issues. It is a safety issue. It's not a matter of common sense as to how many amps you draw from a 14-50 attached to a 30A circuit. It takes knowledge to lower the amps to 24A. Some people don't understand why they couldn't set it for 30A. Others, even you, might forget to set it down to 24A if your mind is elsewhere. 240V circuits should be as idiot proof as possible. Your setup of a do it yourself 14-50 on a 30A circuit is just an accident waiting to happen. Code exists for a reason.
     
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  6. azred

    azred Member

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    Make sure you check batteries in your smoke detectors and sleep lightly.
     
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  7. BerTX

    BerTX Active Member

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    Pillory schmillory...
    [​IMG]
     
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  8. voltaren

    voltaren Member

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    Do this. Do this. Do this.
     
  9. 8lincoln30

    8lincoln30 Member

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    Already ordered the adapter and the 14-30 receptacle. I appreciate y'all's advice. Don't call the inspector on me until next week!
     
  10. EVCarGUy

    EVCarGUy Member

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    Thanks!

    Not to beat you up - this is an FYI to anyone still reading. The safety issue is that the car sometimes forgets the current setting at a location (or the GPS location is messed up for some reason, so it treats your house as a 'new' location). The car will try and suck 40 amps because the end of your UMC has the NEMA 14-50 plug on it which tells it that 40A is 'good'. In your case, with a 30A breaker, hopefully that breaker opens before any serious electrical harm occurs.

    Full disclosure - I definitely have a pile of adapters that go to a 14-50 receptacle so I can use my UMC at lots of places, and the responsibility is on me to set the current right. And, I do because I use the adapters so rarely. But, if were using the 14-50 plug at home on something that didn't supply 40A, I _know_ that I wouldn't check the current settings every single time I plug in at home (because that screen doesn't appear until you get out of the car and plug in the cable). I know that eventually the car will 'forget' my home settings and draw 40A and I won't notice it on the car's screen.
     
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  11. SomeJoe7777

    SomeJoe7777 Marginally-Known Member

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    This.

    Easy, inexpensive, up to code, safe. Done. :D
     
  12. 8lincoln30

    8lincoln30 Member

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    Done. Thanks again for the advice.
     

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