TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker or making a Paypal contribution here: paypal.me/SupportTMC

72A charging option

Discussion in 'Model S: Battery & Charging' started by desidon, May 4, 2016.

  1. desidon

    desidon Member

    Joined:
    Feb 14, 2016
    Messages:
    43
    Location:
    TX
    Hey folks...I recently placed an order for a Model S with the 72A option in it. I admit that I did not do full research on it and checked the box.
    Now it is time to install 240 V circuit in the garage etc and looks like the 72A option is useless until I get the HPWC installed at home as well. Is that true?
    If yes, these things have a 5 week lag time and the car will probably be here in 4 weeks!
    What do I do? Get regular 240V first and pay a guy again to do the HPWC?

    Thank you in advance
     
  2. desidon

    desidon Member

    Joined:
    Feb 14, 2016
    Messages:
    43
    Location:
    TX
    Typo...I meant the HPWC has a 5 week lead time when I went to place an order.
     
  3. Cosmacelf

    Cosmacelf Active Member

    Joined:
    Mar 6, 2013
    Messages:
    3,399
    Location:
    San Diego
    Yes, you need the HPWC to charge at 72A. A regular NEMA 14-50 receptacle will allow you to charge at 40A. If you want the HPWC, I would go ahead and start that process. You can always limp along charging using 120V until the HPWC is installed.
     
  4. TexasEV

    TexasEV Active Member

    Joined:
    Jun 5, 2013
    Messages:
    3,790
    Location:
    Austin, TX
    It's not useless. It just means you won't be using it at home when plugged into a 14-50 outlet. You would just be drawing 40A then, but that's ok as that is enough to charge overnight. The 72A charger is useful when traveling and you can plug into HPWCs at destinations (or the rare high amp J1772-- there are 2 in Texas that I know if) and get faster charging when you need it, which is when you're away from home.
     
    • Helpful x 1
  5. brkaus

    brkaus Member

    Joined:
    Jul 8, 2014
    Messages:
    963
    Depends on your home configuration.

    Do you have capacity for 80A?

    How far are you running the circuit?

    Will you eventually want more than one power source for future cars?

    Depending on answers to above, you might consider running 100A (or 80A) to a location you would like the plug.

    Add a small panel at this location and install the 14-50 off the panel. If you upgrade later, you can always add the additional hpwc off the subpanel as well.
     
  6. Rocky_H

    Rocky_H Member

    Joined:
    Feb 19, 2015
    Messages:
    896
    Location:
    Boise, ID
    I think perhaps you are looking at it wrong. I think more than a 50A circuit for charging at home is pretty useless, because you’ve got all night, but having the 72A capability for charging on trips can be really handy. I ordered in a really annoying point in time in Tesla’s history. In January 2014, they had the second charger and the high power wall connector as one bundled option; you could not choose one or the other, and it was I think almost $4,000. I was kind of considering the dual charger capability in the car for trips, but had no use for the higher power wall connector at home, so I skipped that option. Later, they unbundled those two again. So I would just stick with the 14-50 at home and not waste the money.


    However…that is fine for the convenience if you are just going to leave your mobile cable plugged in at home and hanging on the wall, as I and many others do, if you are fine not needing it in the car with you driving around town every day and only pack it up for taking on trips. Putting it in the car every day is going to get old fast. So, if you are planning to buy a second SOMETHING so you can have a connection at home and in the car, then I would recommend getting a wall connector, because now they are only about $550, while another mobile cable is $650. Still wouldn’t need to change the math on the circuit, though. You can install a wall connector on a 50A breaker circuit.
     
  7. MorrisonHiker

    MorrisonHiker Beta Tester

    Joined:
    Mar 8, 2015
    Messages:
    1,925
    Location:
    Morrison, Colorado, USA
    I haven't seen it discussed much but I noticed a while back that they actually lowered the price of the UMC bundle to be $550 as well: Mobile Connector Bundle
     
  8. Rocky_H

    Rocky_H Member

    Joined:
    Feb 19, 2015
    Messages:
    896
    Location:
    Boise, ID
    Ah, thanks for posting that. When they first came out with the new wall connector, the mobile one was still $650 for a while, which didn't make a whole lot of sense, since the wall connector is capable of higher power levels. That's good that they fixed that odd pricing issue.
     
  9. davewill

    davewill Member

    Joined:
    Feb 5, 2014
    Messages:
    437
    Location:
    San Diego, CA, US
    Others have reported that their shipments are coming much sooner. I would go ahead and get the HPWC ordered. Then have the high amerage circuit run, but have the electrician put in a 14-50 and a 50a circuit breaker if the HPWC doesn't come soon enough. When it does show up, he can change the breaker and wire the HPWC in, but I bet you get it soon enough.
     
  10. Chaz

    Chaz Big Kahuna

    Joined:
    Mar 9, 2016
    Messages:
    158
    Location:
    Colorado Springs, CO
    This was exactly my plan. Install a 50a breaker for a NEMA 14-50 outlet, but using the higher gauge wire that would be required for a 100a circuit once my WC arrived. Then, I could just swap out the breaker from 50a to 100a, and remove the 14-50 outlet and replace with the WC once it got here. No need to run another wire.

    However, my WC arrived three days before my scheduled install (in just 2.5 weeks after ordering), so I ended up not needing to implement this plan. :)
     
  11. desidon

    desidon Member

    Joined:
    Feb 14, 2016
    Messages:
    43
    Location:
    TX
    Appreciate the responses folks. Below is what I got back from the master electrician guy that came and took a look. I had asked him about a 50 amp option first and then going up to a HPWC per recommendations above.
    Is the assessment below reasonable along with the costs?



    HPWC Option

    Install a 90 amp, 240 volt circuit to supply the High Power Wall Charger (for your on-board charger set at 72 amps).

    The circuit will have its own tap from the main meter socket outside. The existing panels are loaded to the point that adding 80+ amps of load could cause the main breaker to trip.

    Wiring will be installed from the 1 car garage, lower attic, to the upper attic and back down to the attic over the garage. We will possibly need to remove drywall from the ceiling in the one car garage.

    Includes installing customer-supplied Wall Charger, in the two car garage, on the left side inside the storage cabinet.

    We will install a safety disconnect near the Wall Charger.

    Includes permit and inspection.

    Total cost: $2,300.00.

    Note: we will not be able to install a 90 amp and 50 amp supply together. Options would be:

    No simultaneous charging

    Stepping down the Wall Charger to 50 amps, which would allow both chargers to work simultaneously.
     
  12. CSFTN

    CSFTN Member

    Joined:
    Aug 24, 2014
    Messages:
    470
    Location:
    Memphis, TN
    FlasherZ usually shows up and gives a definitive answer by this point. Point 1) there is a National Electric Code which provides guidance and maybe, according to your locality, regulation on this Point 2) what really matters is what your electrician thinks is safe, and if you have inspectors what they think is safe Point 3) you can't run a 10-50 outlet on a circuit which has a > 50 amp circuit breaker. If you want both a wall charger at > 50 amps and a 10-50 outlet, you will/should need 2 separate circuits including 2 separate circuit breakers. I think.
     
  13. davewill

    davewill Member

    Joined:
    Feb 5, 2014
    Messages:
    437
    Location:
    San Diego, CA, US
    It sounds like he misunderstood that the 50a was just supposed to be temporary lashup if the HPWC doesn't come in on time. See if you can explain that to him better. Also, consider if it's only a week gap between the car and the HPWC just limping along with 120V and/or public charging for that week.

    As far as the price, it might be about right given the the amount of work he described. If it were my house, I'd get a second quote, and I'd get a quote for a 50a circuit. If they can do the 50a without having to go to so much trouble and expense, I'd consider just doing that. At that point, it becomes a personal choice whether you use the UMC that comes with the car, or go ahead and install an HPWC, anyway.
     
  14. Rocky_H

    Rocky_H Member

    Joined:
    Feb 19, 2015
    Messages:
    896
    Location:
    Boise, ID
    It sounds like a big portion of that cost is the part about having to do a separate run to your house because of your existing panel not being able to handle an additional 80-90 amps of load. I might recommend looking at what Dave said here. Depending on how much you drive, a 50A circuit, or maybe even 40 or 30 might be fine. For some panels, you can replace two 120V breakers with what is called a “tandem breaker”, that fits two in the space of a single to free up some room. That might be able to make some physical space. And then, if you have the electrical capacity available, maybe you could put in the wall connector on a 40 or 50A circuit. The wall connector does have a switch inside to set it to many different levels of circuit.
     
  15. FlasherZ

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

    Joined:
    Jun 21, 2012
    Messages:
    7,019
    This is what I did for my second HPWC.

    There are some special rules here that must be followed if you do this. First, your service rating from the power company needs to be greater than the main breaker you currently have (e.g., 400A service but only 200A panel, or 200A service but only 100A panel).

    Second, you'll need a service disconnect that is co-located with your existing main breaker. Code requires that you be able to stand in one place and turn off all power to the building with less than 6 breaker throws. You also require this disconnect to be as close as possible to the entrance of the power, because conductors from the bottom of the meter are unfused.

    Then you'd run the conductors to your garage.
     
  16. skip8jj

    skip8jj Member

    Joined:
    Aug 19, 2015
    Messages:
    69
    Location:
    Portland, OR
    @disidon, Our installation is similar to what your electrician proposed. Ours tapped the lines just after the meter and ran a circuit about 45 feet, including through a 6" concrete wall, to a disconnect behind the car on the wall. The HPWC is located just under the disconnect. Our service is only 70 amp so the dedicated EV circuit disconnect is fused at 40 amp and the HPWC is set at 32 amps. The cost was just shy of $2,000. It has taken almost two months to get the final inspection approval. For approval, I supplied a copy of our electrical usage, ~4 kWh / day, over the last year, and name plate data from for the oven. The stove top is NG. The electrician had to furnish the city with a load calculation. We live in a condo which supplies laundry, heat and hot water, no A/C.

    Our MS calls for charging at midnight and takes it to about 75% of full charge. If we know we are going to want more charge, we initiate more charge when we wake up in the morning. By the time we are ready to leave, the battery is at 100% or close to it.
     
    • Like x 1
  17. timk225

    timk225 Member

    Joined:
    Mar 24, 2016
    Messages:
    184
    Location:
    Pittsburgh
    I am wondering how many people really NEED the HPWC. Yes, it charges faster than the 14-50, but for how many people is the 14-50 not enough?

    And I am willing to bet that for those who say the 14-50 isn't enough, it still is adequate most of the time, and it is only unusual occasions in which a higher charging rate is needed.

    Remember, when comparing the cost of buying gasoline to electric charging, every dollar you spend unnecessarily beefing up the electrical system is more miles you have to drive on electric to save back that extra money.
     
  18. desidon

    desidon Member

    Joined:
    Feb 14, 2016
    Messages:
    43
    Location:
    TX
    The P90DL is costing around $140k plus so gas savings is not in picture.
    This is for the wife.. I wake up most mornings to see her iPhone at around 2% battery left. She just does not charge it before going to bed. She isn't wired that way....dunno... Don't ask :)
    So 72A when I was checking the box was more to help a use case where she does not charge overnight... Wakes up the next morning, realizes it and has maybe an hour or so before going to work.....
     
  19. desidon

    desidon Member

    Joined:
    Feb 14, 2016
    Messages:
    43
    Location:
    TX
    Also the HPWC came in yesterday. The site says that 5 weeks delay but got it under 10 days.
     
  20. wdolson

    wdolson Active Member

    Joined:
    Jul 24, 2015
    Messages:
    2,520
    Location:
    Clark Co, WA
    I probably don't. I work at home and don't need to commute. However, I see the HPWC as a convenience. With 14-50 charging, you either have to use the charger cables provided with the car or buy a separate set (which costs about the same as an HPWC). If you are using the set that came with the car, you have to bundle up the cable and put it back in the car every time you leave, or leave the cable in the garage and risk getting stuck somewhere without a charging cable when you need it.

    The HPWC is permanently mounted on the wall and doesn't go anywhere. When you leave you hang up the cable and go. Nothing is going to get misplaced or lost. Always knowing where something important is of high value to me.

    As for the cost of installation, if I was going to use a 14-50 plug, I was either looking at running an extension cord from the laundry room where we have an unused 14-50 plug for the dryer, or installing a new one in the garage. The cost of installing the circuit for the 14-50 is the same as installing the HPWC. The extension cord was obviously just a short term fix and something permanent had to be done.

    I did initially order the car with the 72A charger enabled, but after talking to the electrician and evaluating our power situation, a new 60A circuit is about the best he could do, so I downgraded the car to the 48A charger. If I move and install a 72A HPWC down the road, I can always pay Tesla to turn on the extra charging capacity on the car.
     

Share This Page