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New Wall Connector :)

Discussion in 'Supercharging & Charging Infrastructure' started by pluginx007, Apr 12, 2016.

  1. XLR8OR

    XLR8OR Member

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    I've read this entire thread, and am impressed with the braintrust here. May I tap into it?

    An electrically-savvy buddy and I are installing a Wall Charger v2. The car is a MS with the 72a charger upgrade. Tesla says the WC needs a 90a breaker, which we have installed in a 200a main panel. The load calcs even with a 100a breaker show there is plenty of capacity to service concurrent loads throughout the house with the additional breaker. We have run 4AWG and 6AWG for the ground through 1" rigid EMC from the panel across the garage ceiling and down into the top of the WC mount, connecting them to the block inside (pics below). Total run is about 15'. All good so far, I think.

    As others have discovered, there are odd inconsistencies and omissions in the manual. We're about to attach the WC guts to the mount and before i power it up I want to make sure of a couple of things. The 4AWG pigtails connect to the green block, of course. The ground pigtail surely must connect to the aluminum block on the PCB (see pics), but the manual is silent on this. The rotary current dial is set to "C", which is the setting for 72a of output. An inconsistency on the DIP switch: the manual says about position 1 that UP is for "Line to Neutral (277v) and DOWN is "Line to Line (240v)", yet the sticker on cover panel (pic) says UP is "Line to Neutral (220V)" and DOWN is "Line to Line (240v)". The unit shipped with position 1 UP. I apologize for being dense, but shouldn't it be DOWN "Line to Line (240v)" for US residential service?

    Thanks for your input on this, or anything we screwed up!
    IMG_2507.JPG.jpeg IMG_2509.JPG.jpeg IMG_2508.JPG.jpeg IMG_2513.JPG.jpeg
     
  2. CmdrThor

    CmdrThor Active Member

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    The ground does indeed connect to the obvious lug, that's how I did it at least.

    Yes, you want that dip switch to be DOWN, Line to Line 240v. The inconsistency between the label and manual is just the fact that the manual indicates up to 277V is supported for line to neutral instead of just 220V on the label. I do remember needing to change that switch.

    I would have went with 3AWG rather than 4. 4AWG I believe is rated for 85 amps so you would want to limit your continuous load to 80% of that which is 68 amps. To be safe you should probably set the rotary switch to B for 64 amp charging. Perhaps someone with more knowledge of the NEC might know better though.
     
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  3. XLR8OR

    XLR8OR Member

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    Thank you. However, the factory pigtails are 4AWG and you can crank up the unit to deliver 80a to older MSs with dual chargers. Perhaps wire length is the reason? Happy to learn earn more.
     
  4. ccutrer

    ccutrer Active Member

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    Just because internal connections use smaller wire, doesn't mean you're allowed to as well. The UL should list the wall connector as a whole, and because of that the internal connections are not subject to NEC. Basically they're allowed to use smaller wire because it's a very short distance, and the enclosure is consistent, controlled, and tested for heat transfer etc.
     
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  5. XLR8OR

    XLR8OR Member

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    ok, got it, thanks
     
  6. Galve2000

    Galve2000 Member

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    It is nice that the new HPWC still supports 80 amps for older dual-charger vehicles. If loads allow at your site I wish everyone would future proof and install a 100 Amp circuit with the appropriate wire size.
     
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  7. ccutrer

    ccutrer Active Member

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    It also means in a daisy chain configuration, you can utilize all 80A charging two cars at 40A apiece. I really wish they made it even more flexible though - something like "you have 125A total load that you can share between these three or four wall connectors. But each individual one can only max at 60A"
     
  8. FlasherZ

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

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    #4 is limited to 85A at 75 degC termination temperature, which would limit you to the 64A charging / 80A breaker setting.

    This is, unfortunately, a place where even a lot of electricians mess up. They're either unfamiliar with the continuous load rules and think "80A charging? Wire's good to 85!" without considering the continuous load rule; either that, or they're so used to provisioning entire dwelling units with 100A service on #4 (which is legal)... it's just not legal for branch circuits.
     
  9. Hammer@OR.US

    [email protected] What a long strange trip its been.

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    I have seen this in the code but never understood the rational, can you explain why this is?
     
  10. cranker2k

    cranker2k Member

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    I wish their is a design for a retractable cable, so that when not used, there is no visible loose cables. I'm willing to pay couple of hundred dollars more for that!

    ______________________________________________________________________________________________
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  11. AZ Desert Driver

    AZ Desert Driver Rare combination

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    You just scared me....My house has a 200 amp main panel, and I'm trying to install a 100 amp branch for my Tesla. My plan was to install 2,2,2,8 THHN in a 40' trench to a sub panel - then into a 14-50 and a 120VAC. Perhaps build a HPWC in the future. One prospective contractor said he wanted to change into all aluminum wire because there is a 30" segment behind drywall into the sub panel. No one has even looked to see if the 200 amp supply (could it be only #4?) can support a 100 amp branch.
    How do I get comfortable that the electricians know what they are doing?
     
  12. FlasherZ

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

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    The idea is that you will rarely, if ever, run your household at 100% for long periods of time. They figure that nearly every household load is intermittent - and that clause is only applicable to an entire "dwelling unit".
     
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  13. FlasherZ

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

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    200A service won't be #4 - only 100A service can be fed with #4 (copper - aluminum won't feed 100A).

    THHN is an individual wire - are you talking a cable assembly, or individual wires in conduit? I'm confused as to your contractor's reasoning behind aluminum wire?
     
  14. AZ Desert Driver

    AZ Desert Driver Rare combination

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    I too am confused with that quote. I have a plan that I posed to 5 prospective contractors - and let them develop that plan into a bid that includes their expertise at converting homeowner wishes into responsible design.
    My plan was to run 2,2,2-8 in 1-1/2 PVC conduit from 200 amp main panel, beginning with a new 100 amp breaker (taking the slot of an unused 30 amp breaker). Next is 48 feet of trench across lawn to the side of my garage. Going up the outside wall about 18", entering into a junction box and penetrating the wall into the garage. Next, go up inside the wall to 48" and enter a new sub panel fitted with a 50 amp breaker and a 110 V 20 amp breaker. Next - short run to 14-50 plug and a 4 gang 110 GFI box. All flush mounted.
    Somehow, my plan told one contractor that #2 wire had to be temperature derated to a #1 aluminum system because of the 30" run from garage wall penetration and sub panel could not be inside the wall unless upsized for the entire run. I don't get this. His bid was $2600. I was hoping for a bid much less. As soon as I said "Tesla", attitudes changed from EV system to bilk-him. I'm now trying to retreat into a simple 50 amp circuit. I thought it would be good to install a 100 amp system while I have the trench open for possible future expansion.

    Where did I go wrong?
     
  15. scaesare

    scaesare Well-Known Member

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    Cool, but not cheap: HPWC Cable Reel
     
  16. cranker2k

    cranker2k Member

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    Nice setup having a reel in the attic! However I don't think I have that luxury. The cable in the reel doesn't have to be that long (to retract and held in a housing), so even with #4 cable such housing + charger can be all-in-one?

    ______________________________________________________________________________________________
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  17. FlasherZ

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

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    You can't run THHN in that case, because conduit is considered wet location when outside. THWN rating is minimum for that run.

    Is this garage attached or detached? If detached, you can't have multiple feeds going to a detached structure, so if there's any other power in there you will have to consolidate to a subpanel. If attached, you're a-ok.

    I think I understand what he was saying... if multiconductor (e.g., a 2-2-2-8) SE/SER cable is used inside thermal insulation, you must use the 60 degree column for ampacity. #2 copper @ 60 degC is only good to 95A. So he's looking to put you at #1 AL so that you can meet 100A requirements. If you were to use all conduit (instead of SER cable), then you could use #2 THWN without a problem.
     
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  18. tga

    tga Supporting Member

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    This just occurred to me - where is the dividing line between attached and detached? If the garage is connected to the house with a mudroom, I'd call that attached. What about an enclosed breezeway (with doors and windows)? What about an open breezeway (roof held up by columns)? I guess this could be one of those "up to the AHJ" cases...
     
  19. FlasherZ

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

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    The most common definition is if it is considered a separate structure -- or if there's the ability to run conduit to it without having to span open air or require a trench/direct bury. An open breezeway renders it attached -- we have a local subdivision where rules on outbuildings were defeated by building a permanent, masonry faced breezeway to make it a single "structure".
     
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  20. tga

    tga Supporting Member

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    Thanks. That means I can run a subpanel to my attached-via-an-enclosed-breezeway garage, but leave the existing 15A garage circuit in the main panel in place. The battery of T5HO's will run off the sub, but I'll still have basic lighting if the sub breaker ever trips.
     

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