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UMC, Corded & Wall Chargers do not use Neutral?

Discussion in 'Model X' started by Zinfandel, Jun 12, 2018.

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  1. Zinfandel

    Zinfandel Member

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    I am installing wiring to initially support a NEMA 14-50 outlet but later a Tesla Wall Charger. I want to oversize the wire gauge for the NEMA 14-50. If NONE of Tesla's home chargers use the neutral leg, I will save money and time by not including the neutral wire. Am I understanding this correctly?
     
  2. JasJ

    JasJ Supporting Member

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    True, but if you're running a 14-50 first, run a thinner/cheaper (but appropriate for 50A) gauge neutral so you are not violating code by installing an outlet without a neutral, could be quite dangerous for non-Tesla use.
     
  3. boaterva

    boaterva Supporting Member

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    Yes, BUT a 14-50 still needs the neutral wire to be installed to code since a 14-50 itself needs the neutral wire. See Flasher's FAQ in my sig for more.

    Anything that is STRICTLY 240 VAC does not need it, since you are using only the two legs of the 240 supply. Anything that could theoretically peel off one of the legs and supply 120VAC to something (using the neutral) has to have a neutral, and that's why the 14-50 requires a neutral.

    SO, a 14-50 needs a neutral, BUT wires run strictly for an HPWC do not. Since there is no 120 use there and can't be one.
     
  4. Malbrough

    Malbrough Member

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    Correct. For a the HPWC, some installers in my area use Romex 6/2 (has black, white and ground) and they just mark the white wire with red tape or paint on each end to designate it as a power phase and not neutral. Or they use 6/3 (has black, white, red, and ground) and not use the white wire. I think it just depends on what they have in the truck when they show up for the job. Both of those wires are rated at 55 amps.

    I would think that for the NEMA 14-50 on a 50 amp breaker, they would need to install all 3 conductor wires and the ground to meet code. It's not that much more expensive for 6/3 compared to 6/2 (looking at Lowe's website). The labor is what costs the most. To install a NEMA 14-50 near the breaker box here costs around $250, last I checked.
     
  5. teethdood

    teethdood Member

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    Don't cheap out. Problem is that someone else in your family or the next homeowner will not know this and plug in another device that needs the neutral to work safely. Kind of like installing a 3-prong 120V adapter to plug into an old 2-prong outlet. It'll work, but safety is not guaranteed.
     
  6. markb1

    markb1 Active Member

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    If you don't want to run a neutral wire, a NEMA 6-50 receptacle is the correct one to use. It does not have a neutral pin, but it is still a 50A receptacle, so your car will charge at the same rate. Tesla sells a UMC adapter for it.
     
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  7. Derek Kessler

    Derek Kessler Member

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    You are correct that a 14-50 plug does have a neutral line and that Tesla chargers do not use it. But if you are installing an outlet you ABSOLUTELY MUST install it with the correct wiring. Just because you don't need it now for your car doesn't mean somebody else won't later down the line.

    This level of electrical install is easy, but the kind of power we're talking about is not to be toyed with. Do it right or don't do it at all.
     
  8. ewoodrick

    ewoodrick Member

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    It's pretty common for folks with single air conditioner campers to use an adapter to plug into a NEMA 14-50 to run the camper. This requires the ground to get 110V. If it is not there, well, I don't want to see the results.

    Just do it right. You spent $100k+ for the car, don't skimp on $50.
     
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  9. Zinfandel

    Zinfandel Member

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    Thanks to all; very helpful posts.
     

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