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Home Wiring/Breaker Sizes

Discussion in 'Canada' started by wolfblass, Sep 5, 2016.

  1. wolfblass

    wolfblass New Member

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    Sep 5, 2016
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    Location:
    Toronto
    I'm ready to install the required breaker and wiring for future electric charging and wanted to understand the best sizing for wiring and breaker. What is the maximum size breaker for use on a 6/3 copper cable with less then 20ft run from breaker to receptacle. I have seen 50amp breaker for 6/3 wire that would allow 40 amps current to vehicle, can I use 80 amp breaker on #6/3 and provide 64 amp current to vehicle? I'm assuming this would allow quicker charging time to vehicle.
     
  2. rypalmer

    rypalmer Member

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    Aug 22, 2014
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    Location:
    Canada
    Depends on the jurisdiction. You'd have to consult an electrician.
     
  3. KJD

    KJD Member

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    Dec 14, 2013
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    Location:
    SLC, UT
    I would never put an 80 amp breaker on a circuit with 6/3 wire. It would not be safe.
    http://www.cerrowire.com/ampacity-charts

    My car has a 40 amp charger. The new cars have either a 48 amp charger or a 72 amp charger. It depends on the car if a larger circuit will charge the car faster or not. In my case the answer would be no.

    Lots of good information in the home charging FAQ written by FlasherZ.
    FAQ: Home Tesla charging infrastructure Q&A
     
  4. GSP

    GSP Member

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    Dec 28, 2007
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    1,996
    To go higher than 40 Amp charging (50 Amp circuit breaker) you can't use the UMC that comes with your Tesla. You will need to buy the HPWC.

    While having the HPWC and keeping the UMC in the car is the ultimate setup, 40 Amp charging is plenty fast enough for overnight charging. Charging faster than that is nice on the road, but is only useful at home in rare situations.

    GSP
     
  5. BerTX

    BerTX Member

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    May 2, 2014
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    Location:
    Texas/Washington
    A 50 amp breaker is the largest you can put on #6 wire. 40 amps is the largest continuous load you can put on that circuit.

    If you want to charge at a higher rate, you'll need bigger wire.
     
    • Helpful x 1
  6. Goran

    Goran New Member

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    Sep 24, 2016
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    Location:
    Winnipeg, Canada
    Do not run a #6/3 wire on 80A breaker, drawing 64A. Either upgrade your wiring to #4 or keep the #6 wiring and install the 60A breaker and set your charging current to 48A. You must observe the 80% rule between the breaker size and current draw. Your current draw should be within 80% of the breaker rating.
     
  7. RAM_Eh

    RAM_Eh Member

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    Dec 10, 2013
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    Location:
    Toronto ON
    Wrong.

    I am an electrician and this entirely depends on the location.

    Ontario: Use the proper cable with the right insulation value and you can drive 60A through a number 6 AWG cable. If you use house wire (NMW) you will only get 50A out of it. If you use armoured or teck cable you can get the full 60A. Cable in not de-rated in the Canadian electrical code, Only the breaker.
     

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