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nema 14-50/ 100amp main panel and A/c

Discussion in 'Model S: Battery & Charging' started by therealmrmike, Jul 7, 2018.

  1. therealmrmike

    therealmrmike Member

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    I have a nema 14-50 I charge at 40amps every night that works great. problem is I still have a 100amp main panel. I have always been concerned about running the A/C while charging not wanting to trip any breakers and what not. During these hot days when I need A/C all night I could just lower the charge rate in the car to 20amps and obviously it would take twice as long to charge but would be no where near overload the panel. Or is since its still a 50amp breaker Its still 50amps on the panel?
     
  2. lvrouter

    lvrouter Member

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    Henderson, NV
    The amps at the panel are whatever the car is currently drawing. I set mine to charge at 11pm, at that time all of the AC units in the house except master bedroom are set to 80 and generally don't run much if at all. After summer is over I'm going to switch to NV Energy's program that charges less at night and more during the day.
     
  3. mongo

    mongo Well-Known Member

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    If you aren't running an electric stove or oven or electric water heater or electric heat at night, AC plus 40 amps is not a problem.
    If you set the car to 20 amps, that is all it is drawing. The 50 Amp breaker protects the house wiring in the event a fault tries to pull more than 50, it does not force a current draw.

    You can read the power draw for your house at the meter to see what your base load when all your usual loads are on. Want to be under 40-50 amps without charging (assuming 40 amp charge rate).
     
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  4. NickFie

    NickFie Member

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    FWIW, I’ve had lowest energy consumption by cooling house to 72 at night, when AC is most efficient due to cooler night air and no sun heating the house. Gradually step up temperature during the day, reaching 76 in the afternoon. Higher temperature if it’s comfortable.

    This stockpiles “coolth” when it’s cheapest to make and lasts longest. Then use up the stockpile to minimize cooling effort when it’s least efficient.
     
    • Informative x 2
    • Like x 1
  5. therealmrmike

    therealmrmike Member

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    I normally am able to do that but the this week in So Cal where I live its been 115/80 so this week to start out the morning at 75 I am lucky.
     
    • Informative x 1
  6. mongo

    mongo Well-Known Member

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    If water usage isn't an issue, you can run a dripper over the condenser coils to boost efficiency.
     
  7. ucmndd

    ucmndd Member

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    California
    +1, don't worry about it.

    FWIW I drive 120 miles a day and charge overnight at 32 amps. Plenty of time for the car to finish.
     

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