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30 amp to 50 amp

Discussion in 'Model S: Battery & Charging' started by napabill, Nov 24, 2012.

  1. napabill

    napabill Active Member

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    I have a NEMA 14-30 plug that is currently unused. As it happens, it is located in our laundry on the wall shared by the garage. I'd like to convert that plug to a 14-50 and locate on the garage side. Would an electrician (not me!) be able to use the wires for the 14-30? Obviously would have to provide a new plug, and replace the 30amp breakers with 50 amp breakers. Am hopeful I won't have do any rewiring. Would probably leave the 30amp plug and use it if it turns into a major project.
     
  2. Doug_G

    Doug_G Lead Moderator

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    No, he would almost certainly need heavier gauge wire. They don't usually run oversized wires.
     
  3. Zapped

    Zapped Model S - PURE EV

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    I just had a NEMA 14-50 installed. They used #6 gauge wire for the 50 amp circuit. 30 amps would be a lighter #8 gauge wire
     
  4. dailydriver

    dailydriver Member

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    It would also depend on the distance too. Any circuit will require heavier gauge wires to overcome the power loss due to length.
     
  5. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    30A circuits generally use #10 AWG.

    50A can work on AWG 8, but most electricians will use 6 for ranges (resistive heating loads) or heavy use (like car charging).
     
  6. mknox

    mknox Well-Known Member

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    As has been stated, your wires are probably inadequate. You could look at your typical drive habits and maybe a 30 amp circuit would be fine. A 30 amp circuit would give you 18 ideal miles of range/hour while a 50 amp would give you 31 miles/hour. A 30 amp would be fine for me, but I have nothing currently in my garage, so for the small incremental cost of heavier wire, I'll go for the 50 amp circuit. (I don't have the capacity on my main service to go any higher).
     
  7. ahimberg

    ahimberg Member

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    Any serious concerns with 50A over 8? The solar city installed 6-50 in my garage was done with 8 (less than 25' run) -- I think the inspector said #8 wire, #10 ground or something like that. It will be rare that I'll need a full charge, but 1/2 charge every other week probably on average.
     
  8. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    In most cases, #8 is okay. Some jurisdictions won't allow 50A on #8 NM (Romex) but will allow it on THHN in conduit. You'll be fine.
     

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