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I am not an Electrician

Discussion in 'Model 3' started by teqnic, Aug 15, 2019.

  1. Octo

    Octo Banned

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    The city building department / inspector for electrical required this (L1, L2, N all 3/0 copper and a #4 bare copper ground).

    I asked about the 90s because there’s one section that has four 90s between boxes. This is apparently less about safety/functionality and more about feasibility/difficulty and with long sweeps and the Simpull wires it was possible (but difficult)
     
  2. qdeathstar

    qdeathstar Member

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    What did you do with the neutral wire? There is nothing to connect it to in the wall charger?

    NEC, 358.26 living on the edge with the 4 bends...
     
  3. Octo

    Octo Banned

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    Yeah, it was borderline.

    The 3/0 wires ended in a sub panel. This is not just for the car but for an addition to the house. There’s a 60amp breaker in the sub panel for the wall charger and then three 6 gauge wires (L1, L2, ground) to the wall charger. No neutral.

    This panel will also supply power to a kitchen and the A/C, hence the 3/0 wires.

    Car charges around 40 miles each hour with this setup.
     
  4. pscarroll

    pscarroll Member

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    I took the easier route. I bought a Dryer Buddy, used a long RV NEMA 14-50 extension cord to the detached garage, and manually set the car to charge at 24A (80% of 30A for continuous load). It works, but currently working on getting a proper underground install laid with 60A service to allow charging at the full 48A using the Tesla Wall Connector (which is also necessitating an upgrade in the house service amperage as it's an old house). I plan to keep the Dryer Buddy to use if and when I move to a place I have to rent, great product.
     
  5. voip-ninja

    voip-ninja Give me some sugar baby

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    I ran a neutral wire (in Romex) for my HPWC installation. I did it so that if I ever wanted to repurpose the connection for a different type of charger or other application the neutral was already there. I terminated it in my sub-panel and capped it at the HPWC side. It's exactly what the county inspector had recommended.
     
    • Disagree x 1
  6. jebinc

    jebinc M3 LR AWD w/FSD and white premium interior

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    Same. Ran 4 AWG as well. Future proof for 80 amp service. :)
     
    • Like x 1
  7. Octo

    Octo Banned

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    I’m going to replace my 6 AWG with 4 AWG. It’s about 15ft long and I get quite a bit of voltage drop from the breaker to the Tesla wall unit when the car pulls 48A and the wire gets fairly warm (not hot but feverish warm to be scientific).
     
  8. jebinc

    jebinc M3 LR AWD w/FSD and white premium interior

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    That's exactly why I used 4 AWG for my HPWC. It costs more, but what the heck...
     
  9. liuping

    liuping Active Member

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    I do not recommend doing this. My Model S periodically resets the charge rate to 40Amps.

    If you have to do it, I'd get a NEMA14-50 to NEMA14-30 or NEMA10-30 adapter for the extension cord and put a NEMA 14-30 or 10-30 on the UMC. That way the Tesla will never charge higher then 24Amps. But that's also a lot of adapters, which would make me nervous.

    At a minimum, please check the charge amps every time you do a software update.
     
  10. Akikiki

    Akikiki A'-Lo-HA ! y'all

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    Good points ninjia.
     
  11. teqnic

    teqnic New Member

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    Hey thanks, that definitely helped clear things up. I figured #2 was the better option. Against others recommendations, I will be trying the extension cord route. I will be sure to monitor it during the first few times for excess heat.
    I went with this one: https://www.amazon.com/gp/product/B072KNRY1Y/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

    See those are the cool tricks that us DIY'ers have no idea about. I went ahead and scheduled an electrician to come out on Monday and will learn from him. This Aluminum wiring seems to take a little extra special care, so I'll leave it to the pros. Thanks!

    That was a good point. I almost got one that wanted copper only, that could have turned out bad in the long run. I double checked the one I got and it looks to be happy to receive both copper and aluminum, but I'll let the electrician give me the thumbs up!


    Thanks for everybody's help with this, it definitely made me realize that it's just not worth the risk because of my inexperience. However, there are many who have been successful with extension cords -- so I will take the warning to heart and proceed very cautiously. Hopefully the electrician gives me the big thumbs up on Monday.
     

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