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Noob question. 80A for HPWC?

Discussion in 'Model S: Battery & Charging' started by SpudLime, Jul 6, 2018.

  1. SpudLime

    SpudLime Member

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    #1 SpudLime, Jul 6, 2018
    Last edited: Jul 6, 2018
    I tried a search and I’m sure my search fu is terrible.

    So apologies if this has been asked as nausium.

    Just had my HPWC installed by the electrician. He installed a 60Amp circuit breaker per the recommendation I got from Tesla.

    That being said, the electrician ran wiring that can support up to an 80Amp breaker.

    He said he could do either. I said to do the 60A per what I got from Tesla support. He is coming back next week to install my whole house surge protector at the panel and said he can switch to the 80A at that time if it will work.

    My model S 75D will be here in a few weeks.

    So, can I utilize the 80A circuit breaker and get even faster charging?

    Guy said no cost to swap it out.

    Your advice is appreciative.

    *correction 85Amp CB

    *2nd correction. 80A per the HPWC instruction manual.
     
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  2. MelaniainLA

    MelaniainLA Member

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    75D charges max 48A with HPWC installed or 40 amps with Gen1 cable and 32 amps with Gen2 cable on newer cars. 100D charges max 72 amps. You’re FINE with what you have BUT if it’s free max out he capacity so you have a large buffer.
     
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  3. Krash

    Krash Data Technician

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    FYI, the 75D used to be orderable with the 72A AC charging option, but that option was discontinued last year.

    So if you have guests with higher model or older cars they may benefit in using the higher amp breaker, as may you if get a different car later.
     
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  4. boaterva

    boaterva Supporting Member

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    Right, might as well max it out if it's free and the wiring will support it. Then if you ever get a car with a larger charger, or have someone stop by that can take advantage of it, you are set.

    It would also be useful if you ever want to have two HPWCs in loadsharing/loadbalancing mode. That does need more wiring between the two units, also (for the serial comms between them).
     
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  5. SpudLime

    SpudLime Member

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    Thanks everyone.
     
  6. P85_DA

    P85_DA Supporting Member

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    Max out and post to PlugShare so we can all use :eek:
     
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  7. cmaster

    cmaster Member

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    80A circuit breaker will provide = 80% of 80 amp = 64 amps of continuous output

    So, adjust the dip switch of the HPWC to something that is somethimg less than 64 amps. Cheers!
     
  8. tpham07

    tpham07 Active Member

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    if he'll switch to 80A for free do it. You never know when you might buy a second Tesla ;)
     
  9. Snowstorm

    Snowstorm Member

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    If he will switch to 80A for free, then he is charging too much for 60A. 80A requires a thicker cable that may cost hundreds more (depending on the length of your run). Can you ask for a discount on the 60A?
     
  10. SpudLime

    SpudLime Member

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    I supplied the part. So I guess for free was a bit misleading. The labor is free. Normally a 1/2 hour charge.
     
  11. SSedan

    SSedan Member

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    Sounds like just swapping the breaker since larger cable ision place, which is probably 6 screws. 4 for panel cover, 2 for wires.
     
  12. Snowstorm

    Snowstorm Member

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    If u ever want 2 EV then there would be an advantage to wire a 80A to the garage. Otherwise for 1 car, I don’t think there would be diff between 60 or 80a
     
  13. Krash

    Krash Data Technician

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    12A difference for cars with 72A charging.
     
  14. The Duke

    The Duke Member

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    I ran for 60 amps and cut it back to 35 amps max in the car because that will always fill the car overnight. I am thinking it will be easier on components but I could be wrong.
     
  15. SSedan

    SSedan Member

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    So last winter I got by on a 30amp outlet, but here near Green Bay this is too little to be able to consistently schedule charging to finish up just in time for my commute.
    When cold battery/interior warming actually would consume range.
    Battery warming time is what made charge end time inconsistent.
    Also consider charging itself makes some heat so I thinking you need to charge on the cold there are efficiency benefits to high amperage. Can run the heater and once minimum charging temp is reached can make some additional heat with with charging.

    The 30amp outlet had plenty of time to charge the battery but I am still installing the wall connector, I think it will be worth it in winter and on those once a year quick turn around stops at home, could have saved me a supercharger stop 30 minutes from home a month ago. Got home from a long trip and needed to empty car and get right back on the road due to a family emergency, the slow 30amp plug was good for 4 miles while unloading the car, causing me to make a detour to a supercharger for 10 minutes of juice wasting 20minutes total. Wall connector would have avoided that since the car does have dual chargers.
     
  16. mongo

    mongo Well-Known Member

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    If you go above a 60 amp breaker, you need a local disconnect at the HPWC to be code compliant. You also need to redo the load calculations to ensure your service is adequate.

    I would be wary since the electrician did not mention the disconnect to you, unless there is a sub panel or main panel near the HPWC which will fill the role of the disconnect.
     
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  17. Rocky_H

    Rocky_H Active Member

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    Oh, holy cow. I was reading this thread and was kind of thinking, "hm, whatever." But I had forgotten all about that. Yes, that disconnect switch if it's above a 60A circuit is a solid code requirement, so it might require a different installation. But if the breaker panel is right there in the room with it, most inspectors will consider that as the disconnect switch, so if that is the setup there, then just switching the breaker might be allowed.
     
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  18. bob_p

    bob_p Active Member

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    The disconnect switch is a local requirement - not present in our area. We had a 100A circuit installed for our HPWC in a new house, and all they did was run the 100A wiring in a conduit inside the wall, connecting it directly to a breaker panel - no disconnect switch.

    As for the OP's question about 60A or 80A, we've got two Tesla vehicles. One is using an HPWC on a 100A circuit and the other uses a 14-50 outlet (with Tesla's 14-50 connector). With the HPWC, our 2012 S P85 (which was traded-in 2 weeks ago for an X 100D) would get 80A of charging; our S 100D only gets 48A of charger (because we didn't spend the extra $$$ for the 72A upgrade); and on the 14-50 outlet, our new X 100D only gets 40A.

    For overnight charging, 40A charging (on a 50A) circuit is more than enough to fully recharge a 100 battery pack (up to 90%).

    The only time you need faster charging is if you are driving during the day, and then need to quickly get a large charge before heading out for another round of driving or a road trip later in the day. Though with the supercharger network, if you are heading out on a road trip, it'll be faster to recharge there than on a 60A or 80A HPWC.

    Though if the electrician only needs to swap out the breaker and then change the setting in the HPWC to upgrade to an 80A circuit - the OP should do that, just in case you ever do need a faster charge...
     
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  19. Rocky_H

    Rocky_H Active Member

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    Look, I wasn't just saying that for my health. It most definitely is not just a local requirement. It is National Electric Code Article 625, subsection 43 in the 2017 updated version.
    Quote: "625.43 Disconnecting Means. For equipment rated more than
    60 amperes or more than 150 volts to ground, the disconnecting
    means shall be provided
    and installed in a readily accessible
    location. The disconnecting means shall be lockable open in
    accordance with 110.25."

    Your installation of a wall connector on a 100A circuit without that disconnecting means violates national electric code.

    Here's a link with some discussion on it:
    Interpretation of NEC 625.42 as it relates to 110.25 and 625.19
     
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  20. cmaster

    cmaster Member

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    Yes. I always follow anything above 50 amps to use a disconnect switch.

    Also, 100amp disconnect switch can be had for about 30-50 bucks via ebay btw if anyone is curious.

    Run 2-2-2-4 SER Aluminum to 100amp disconnect switch. Then run 3-gauge CU to HPWC. Will be cheaper to do that.


     
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