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New owner - charging question

Discussion in 'Model 3: Battery & Charging' started by vasuvius, Dec 1, 2019.

  1. vasuvius

    vasuvius Member

    Joined:
    Nov 30, 2019
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    Location:
    Northern NJ & South Berkshire County MA
    We just got a Model 3 Long Range for my wife a month ago.

    I wired a 14-50R receptacle for the charger right next to the circuit panel in the garage using 8AWG wire and a 50A dipole breaker.
    I'm only using the charger that came with the car and it draws 32Amps.

    Should I have used 6AWG wire ? I felt that was unnecessary given the charger only draws 32A and the receptacle is 1 foot from the circuit panel / breaker.

    Also, I see a lot of comments on people installing a wall charger. Apart from the ability to charge faster is there any other benefit to it ? Are there any negatives to just using the charger that came with the car ?

    Thanks,
    V
     
  2. Runt8

    Runt8 Active Member

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    Depending on the temperature rating you can use 8 gauge wire up to 55 amps (see the chart Ampacity Charts - Cerrowire). However, more than likely with a 50 amp breaker you should have used 6 gauge. You could switch to a 40 amp breaker and still use the 14-50 receptacle and not have to change the wire.

    As for the wall connector, there are a few benefits:
    • Can keep the mobile connector in your car so you never forget it.
    • No need to worry about wear when frequently plugging/unplugging.
    • Looks cleaner.
    The first two depend on how far you drive - if you don’t plan on taking the UMC with you then it’s not really a problem. And you can replace a lot of receptacles for $500.

    I ended up installing the wall connector for the faster charging and all of the reasons listed above.
     
    • Like x 1
  3. joebruin77

    joebruin77 Member

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    Location:
    Encino, CA
    Also a lot of utility companies will offer a substantial rebate if you install a wall connector but do not offer the rebate for a 14-50 outlet. My local utility paid me $500 towards the cost of my Wall Connector.
     
  4. srs5694

    srs5694 Active Member

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    Woonsocket, RI
    I don't know enough about wiring to comment on that.

    In addition to the benefits that @joebruin77 and @Runt8 have mentioned, buying a Wall Connector (or a second Mobile Connector or a third-party EVSE) will give you a spare EVSE. As it is now, if your Mobile Connector fails, you'll need to make do with public charging until you can get a replacement. If you've got two EVSEs, then if either one fails, you can use the other one for however long is necessary to get a replacement, with minimal hassle. It could also be handy in debugging a problem -- with one EVSE, if you plug in and your car won't charge, you can't know if the fault is in the EVSE or the car. These factors are most likely to be important if you live far from public charging infrastructure, and especially if the Tesla is your only car.
     
    • Helpful x 1
  5. woodguyatl

    woodguyatl Member

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    GA
    Switch to a 40 amp breaker if you used Romex. No changes needed if you used individual conductors in conduit.
     
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  6. vasuvius

    vasuvius Member

    Joined:
    Nov 30, 2019
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    Location:
    Northern NJ & South Berkshire County MA
    Thanks everyone.
    I used Romex. I guess I'll change the breaker to a 40amp as it's a lot less work.
    I was unable to find 6AWG at any of the local stores and didn't want to order a 25ft spool of 6AWG and have it lying around. It was able to get 5ft of 8AWG and since the current draw was only 32amp I figured it would be OK especially since the outlet is only a foot from the circuit panel.
    Neither the wire nor the breaker even get warm. I usually leave the mobile charger plugged into the outlet.

    I'm not worried about charger issues as there's a Tesla store 3 miles from my house with a large number of superchargers. Also, my wife can drive either of the other 2 cars if needed. I mostly commute on my motorcycle.

    I need to read up on the various wall charging options as I plan to get an electric motorcycle next year (hopefully)
     
    • Like x 2
  7. Runt8

    Runt8 Active Member

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    As long as you only ever plug in the mobile connector, it’s fine. But a lot of the electrical codes are dedicated to ensuring safety without caveats. If you ever sell your house the new owner would have no reason to think that he couldn’t plug in a 50 amp device. If you switch to a 40 amp breaker then the breaker would just trip. But leave it on a 50 amp breaker and you’re looking at a potential fire hazard.
     
    • Like x 1
  8. manto

    manto Member

    Joined:
    May 5, 2019
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    14
    Location:
    San Diego
    Isn't gen2 mobile charger rated 32A max anyway? Why want to go above 32A?
     

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