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Friday the 13th: Scary HPWC Install Estimates?

Discussion in 'Model S: Battery & Charging' started by DIL, Oct 6, 2017.

  1. DIL

    DIL Supporting Member

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    I'm having three different electricians (overkill?) come out to my house on Friday the 13th to provide estimates for HPWC installation. Anything I should know? Or ask? I'll let you know how it goes...
     
  2. DIL

    DIL Supporting Member

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    PS - I have done my research (extensive) on this forum, so I'm aware of the basics.
     
  3. john pane

    john pane Member

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    Just as a reference point, I installed a 100A run to a new 100A sub panel, and then a 100A line from the sub panel to the HPWC. All to code. The materials cost (excluding the HPWC) was about $400.
     

    Attached Files:

  4. ReturnZero

    ReturnZero Member

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    If the HPWC is the only thing on the circuit, is it possible to run the 100A line directly from the main breaker to the HPWC without needing a sub panel? At what point does the sub panel become necessary? I'm planning my installation now but haven't gotten any estimates or anything yet.
     
  5. john pane

    john pane Member

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    For such a high amperage you need a cutoff switch unless your main panel is in sight of the HPWC. Installing a subpanel can accomplish that need at similar expense with greater flexibility.
     
  6. ReturnZero

    ReturnZero Member

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    Hmm, in my case the panel is around the corner of the building. Both outside. Distance between HPWC and corner of wall is about 3-4 feet.

    Code:
     _________________________
    |                        |
    |                        |
    |                        |
    |________________________|X  HPWC
             X
            Main panel
     
  7. john pane

    john pane Member

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    If you stay 60A or less you don't need the cutoff. A 60A circuit is sufficient to charge at 48A.
     
  8. Nda721

    Nda721 Member

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    I got mine done for 1600, direct 100amp to the charger. All to code and inspected. Run was about 90+ feet.
     
  9. DIL

    DIL Supporting Member

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    #9 DIL, Oct 13, 2017 at 2:13 PM
    Last edited: Oct 13, 2017 at 2:41 PM
    Okay, here's the scoop. I'm glad I got four estimates, although it required quite a bit of my time. And indeed, SCARY!

    I tried my best to provide each electrician with consistent information. I'm in the SF Bay Area, not too far from the Dublin SC.

    FYI: I will not do this work myself and I won't have it done without proper permitting. I know many of you will say I shouldn't have told the electrician this was for a Tesla, but I figured they'd find out anyway and I'd rather be up-front. The run is <50 feet.

    Needless to say this process has been more difficult and would appear to be more costly than I anticipated. I'm quite surprised how I got a different story from each individual. Although they were all friendly and professional, it is hard to know what to do...

    Estimates:

    1) $2400 including permitting. Didn't come out physically to my home, but asked a few questions and requested a few pictures of my garage. Gave me a call and thoroughly reviewed the permitting and load calc process for my city. Even went so far as to collect the latest documentation from local city hall and send them over to me. Based estimates on anticipated run length from laundry room subpanel. Everyone else who came for an in person estimate saw the (other) exterior subpanel near the meter and elected to use that instead. Estimate reads "dedicated 50AMP rated, 240Volt, EV charger outlet". Is that correct for HPWC? I specified that in writing.

    2) $2000 not including permitting. This was a bit odd because he knew a lot about Teslas but I had to ask him for the estimate as he was leaving. He gave me a very casual verbal quote for a 60 amp breaker off my exterior subpanel, with conduit to the wall opposite my charge port. He spent a long time complaining about how difficult it was to get a permit from my city then asked me to pull it myself. Not exactly a great salesman. Duration: One day of work.

    3) $1550 including permitting. According to this estimate, I don't have sufficient capacity for HPWC without a full panel upgrade that "cost another client $25,000". So this is the lowest quote, but it's for a NEMA 14-50 plug. The biggest advantage: It can be placed on the post in between garage bays for optimal proximity to charge port. This gentleman seemed very knowledgeable but was contradicted by others? Still expensive? Duration: One day of work.

    4) $2550 including permitting with "20% first time customer discount". This person exclaimed "Good news! You have plenty of capacity here!" Estimate says "From 200 main panel supply, install 100amp subpanel behind main panel in garage. Install a 60amp 220V circuit to Jaybox for h/o car charger..." I asked him several times and he insisted I have 200amps available. Although I didn't ask, I received unsolicited offer to run all wires through attic (not conduit) for a clean look in my garage. He was also convinced that the HPWC came with the car. Duration: 1.5 days.

    Not only are these quotes well above what other people on this forum say they spent, but the electricians seem to have come to wildly different conclusions about what can be safely done? So I'm not sure what to do... TMC, help!
     
  10. arcus

    arcus Member

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    Are the electricians really that much more expensive in CA? All the quotes seem extremely high. I thought the 900 bucks I was given by Tesla recommended electric company here in TX was alreay steep, considering the amount of work involved.

    Possibly other people in CA can chime in, but even the $1550 quote seems excessive.
     
  11. john pane

    john pane Member

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    HPWC is not designed to plug into an outlet, but is hard wired. This means #1 and #3 as quoted are not accomplishing your goal.
     
    • Helpful x 2
  12. speedy

    speedy Member

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    You didn't mention what charger you have in your car. If it's 48A, then all you need is a 60A circuit to your HPWC. Even a 50A circuit will give you about 29 miles/hour charge at 40A, which should be more than enough for overnight charging. There is no point installing 100A unless your have a 72A charger in your car and you really need to charge that little bit faster.

    The HPWC can be set for various maximum charge rates, so can handle everything from 50A to 100A circuits, so figure out what is the best option for you and don't install a larger circuit that you need or the car can handle...
     
  13. ReturnZero

    ReturnZero Member

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    What company did you end up going with?
     
  14. Hey_Hey

    Hey_Hey Member

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    I'm doing the same thing right now, and the prices are pretty pricey. My house has 400 amp service that is split into two 200amp panels on the exterior. The two 200amp exterior panels are on the opposite side of the house. One of the 200amp panels services the inside of the house and the other is the HVAC disconnect and an exterior plug. I have two interior 100amp subpanels, neither of which are in the garage.

    The two options we have are:

    1. Run install a 50amp breaker and run a new circuit from an upstairs closet, through the floor, and into the garage which would enable me to charge at 40 amps. That has been estimated to cost ~$1200.

    2. Supply a new subpanel with 100amps from one of the HVAC cutoff panels on the opposite side of the house. That would entail going "up and over" the house by way of the soffit above the panel and into our attic before crossing the attic and entering the garage. The total run would probably be ~100-125 feet. From there, a 100amp subpanel would be installed and a run would go to the HPWC. One Tesla recommended installer estimated $3100-3800 if he charged material and time. He hasn't supplied me with a guaranteed bid because he thinks it will be significantly higher. The other gave me a soft quote of $4000-4500 but would "put pen to paper" to get a formal bid.

    The first will allow me to charge at 40 amps and would be sufficient for my Model S. However, I think it is likely that we will have another EV in the next 3-5 years (maybe a Model X for my wife and kids to use), so establishing the 100amp service now would "future proof" me when/if we get another EV. The $4000 still seems expensive to me. I was hoping for $2000-2500, but I may have had unrealistic hopes.

    On the plus side, the second company also does solar installs and he told me he could install a 5KW solar system on my roof for $15,000 before tax credits, which works out to $2.10 per watt after the tax credit. I'm still considering that.
     
  15. DIL

    DIL Supporting Member

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    Haven’t bought the car yet.
     
  16. DIL

    DIL Supporting Member

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  17. GSP

    GSP Member

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    @DIL,

    It sounds like all of your quotes are for either 50 Amp or 60 Amp breakers and wiring (which respectively allow 40 or 48 Amp charging). Either should be plenty for overnight charging.

    The HPWC can be configured for any breaker size from 15 Amps to 100 Amps. To get compatible quotes, you need to specify the ampacity of the circuit you want installed.

    I recommend asking each one to explain what ampacity circuit they are quoting, and verify they are hard-wiring the HPWC instead of installing an outlet (such as a "NEMA 14-50")

    Pricing seems high for a 50 foot run. I know CA is expensive in general. Perhaps ask them to quote a 40 Amp circuit (allows 32 Amp charging). This can use less expensive #8 wire, instead of #6, and is still fast enough for overnight.

    The most economical route would be to have a "NEMA 14-30" outlet installed, and buy Tesla's 14-30 UMC adapter instead of an HPWC. You can charge at 24 Amps, which still should be sufficient for overnight if you don't have a long (180+ mile/day) commute.

    Good Luck,

    GSP
     
  18. GSP

    GSP Member

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    @Hey_Hey,

    I recommend your "option 1." A 50 Amp circuit will be plenty fast enough for overnight charging (at 40 Amps).

    When you buy a second Tesla, then you can install two HPWCs on the same 50 Amp circuit, and connect low voltage serial communication wire between them. They will negoiate how to share the available power, and if only one car is charging it will get the full 40 Amps. This should provide plenty of flexibility when needed.

    GSP
     

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