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NEMA 6-50 adapter "engineering"

Discussion in 'Model S: Battery & Charging' started by PhilBa, Sep 9, 2014.

  1. PhilBa

    PhilBa Active Member

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    Yes, I know that Tesla doesn't have this adapter for sale any more.

    I recently got my mother in law to let me install a 240 outlet for my car. She's a nice little old lady who probably uses about 1KW a week in her house. So, I went out to the panel and was taking pictures to send to an electrician for a quote and noticed a 50A breaker. Huh??? In almost illegible writing on the legend was a word that I suddenly realized was "welder". Huh??? So I started pulling stuff away from the wall and discovered a NEMA 6-50 outlet!!! Wow, what a find! No electrician needed, just an adapter.

    Now, I vaguely recall someone posting that you can cut the middle wire pin off of the NEMA 14-50 adapter to get it to work on a 6-50 outlet. I'm now paying the price for my prior disinterest in the 6-50 discussion. For some reason, the search function here thinks there are no instances of "6-50" (there most assuredly are) and adding anything else to the search drowns me in irrelevant hits. So, could some kind soul who knows the issues confirm this for me? I looked up the wiring diagrams and it looks like that is indeed the case. Am I right here? I happen to have a spare 14-50 that I am willing to mutilate for the cause.

    Also, on a somewhat separate note, would such a mutilated 14-50 adapter still work in a NEMA 14-50 outlet? I think that is also the case but again would like to have someone smarter than me confirm that.

    I suppose the alternative is to get a 14-50 socket and swap it out.
     
  2. XrstalLens

    XrstalLens Model S P1327 VIN P01867

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    #2 XrstalLens, Sep 9, 2014
    Last edited: Sep 9, 2014
    A mutilated 14-50 plug won't fit in a 6-50 receptacle. I believe you're thinking of a 14-30, which fits if you cut off the center (neutral) pin. The 6-50 has a narrower blade on one side that won't fit the 14-50 blade.

    You can see below: 14-50 (left), 14-30 (center), and 6-50 (right) plugs. It also looks like the spacing between the blades is different.
    Tesla plug adapters.jpg
     
  3. PhilBa

    PhilBa Active Member

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    Thanks Xrstal. guess that tells me what I need to do.
     
  4. FlasherZ

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

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    As noted, a 14-50 and 6-50 are incompatible.

    You will not be able to install a code-compliant NEMA 14-50 on the existing wiring because you will not have a neutral, and tying it to ground to install a 14-50 is a big no-no. An electrician would need to pull a neutral wire to the location as Tony noted, and if it's served by a 6/2 or 8/2 NM (Romex) cable, it'll mean yanking out the existing wire and replacing with 6/3 - this is because you can't run individual conductors without a conduit. If it's in a conduit, you may be able to pull a neutral through it without swearing too much.

    If this is for occasional use, you might make an adapter cable, well labeled "for Tesla charging only", that would contain a 6-50 plug and 14-50 receptacle. For a more permanent and regularly-used install, install a new receptacle. You could cap off the existing welder wires in the panel and use the existing breaker for the new cable.
     
  5. PhilBa

    PhilBa Active Member

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    Hmmm, I'm not sure that the 14-50 has to have a neutral by code. When I had my other garage wired for a 50A 240VAC circuit with a NEMA 14-50 the electrician was not going to run a neutral. I made him add that in. And, he is pretty much a stickler for code.

    I'm not sure I understand the distinction you are making between "Tesla charging only" occasionally vs more permanent use (like charging more often?). The Tesla 6-50 adapter just omitted the neutral. I found this adapter http://www.corddepot.com/shop/ev-products/nema-6-50p-14-50r-evse-adapter-cord/ Why wouldn't it work OK?
     
  6. markb1

    markb1 Active Member

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    The Tesla 6-50 adapter has a proprietary connector on the other side, so it can't be used for anything other than charging a Tesla. The adapter linked above will work fine for charging a Tesla, but the problem is you can plug other things into the 14-50 side, and some of those things expect a neutral connection.
     
  7. TonyWilliams

    TonyWilliams Active Member

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    If you don't put in a neutral, and don't label it "EV ONLY", should somebody plug in a 14-50 plug from something that needs 120 volts (like a camper / motor home / RV), it won't work at best, and could result in something bad at worst.
     
  8. FlasherZ

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

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    Yes, a NEMA 14-50 requires a neutral conductor. If your electrician was going to put a 14-50 in place without a neutral, then he's not really an electrician. The code itself doesn't always codify NEMA receptacle types (although article 551, detailing RV & RV park requirements, does), but art 110.3(B) states that listed and labeled equipment must be installed per instructions. The device is listed for 125V/250V, and so that 125V voltage must be present.

    Just because something "works OK" doesn't mean it's a) legal or b) safe.

    Technically, the adapter cord you have linked is going to violate code - once because it doesn't provide the appropriate rated voltage for other appliances that need the neutral, and twice because Tesla specifies no extension cords - and that adapter qualifies as one. This may come with insurance/liability implications. Is it safe for use with the Tesla? Yes, technically it's safe, because the Tesla requires only the 250V voltage of a NEMA 14 receptacle and ignores the neutral. Is it safe otherwise? No, if someone uses it for an RV you will experience problems and there is a real risk of damaging appliances due to floating neutral.

    For more permanent installations (e.g., you're using it weekly versus, say, once every month or two), I recommend making the investment in the proper receptacle that matches the appliance you're going to plug in, to avoid the risk. With that said, unlike adapters that allow a 50A load to be plugged into a 30A or 20A outlet, I can say in this case that for Tesla charging only, the adapter you link is relatively safe. You have to make the risk decision.
     
  9. Cottonwood

    Cottonwood Roadster#433, Model S#S37

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    Though they are prized items at this point in time, there are enough 6-50 UMC adapters in the wild that I bet you could find one to buy, but I wonder at what premium. That would solve your problems.

    If you do make a 6-50p to 14-50r adapter, put GIANT labels on it in multiple places that say "Use Only for Tesla Charging, Not for RV's"

    I would consider anything less than several uses a week at your mothers to be "occasional." I am sure your mother would agree on this definition. :wink:
     
  10. linkster

    linkster Member

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    #10 linkster, Sep 10, 2014
    Last edited: Sep 10, 2014
    i would:

    1. Turn the power OFF
    2. Determine wire ga.
    3. Visually inspect 6-50 wiring device
    4. Re-torque all connections at both the circuit breaker and receptacle
    5. Use the "heck" out of that nice adapter ! (good to have one anyway in ones arsenal)

    Tesla: From a practical and safety standpoint, PLEEZE bring back the 6-50 UMC adapter and add a 6-20 and L6-30 so these types of threads will die forever.
     
  11. DaveVa

    DaveVa Sig Perf #236 VIN #484

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    Have you tried calling your local service center and see if they will "permanently" loan you a 6-50 adapter. There were a lot of these issued when they couldn't get the HPWC shipped with the initial car deliveries, because the wiring for the HPWC would support a 6-50 circuit. At one point Tesla had shipped me two, but I returned one to the local SC. I wouldn't be surprised if they had them in a drawer somewhere.
     
  12. Cottonwood

    Cottonwood Roadster#433, Model S#S37

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    Please notice that this adapter leaves the neutral on the 14-50 open. NEMA 6-50P to 14-50R EVSE Adapter, 50A, 250V - Corddepot
    Make sure to put GIANT labels on it in multiple places that say "Use Only for Tesla Charging, Not for RV's"

    6-50p to 14-50r.png
     
  13. smsprague

    smsprague Member

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    Check out my thread on this earlier. People have a lot of opinions (strong) on this. I would just make an adapter with 6/3 wire and not connect the neutral on the 14-50 receptacle. Then use the Tesla 14-50 adapter for the UMC. Label it Tesla only on the rare chance someone might try to use it for something else, I would just keep the adapter in the car. If you leave the plug alone no one can make a mistake by using it.

    Wire on Ebay sold by the foot:

    http://www.ebay.com/itm/6-3-SOOW-SO-Cord-Per-Foot-USA-Portable-Outdoor-Indoor-600-V-Flexible-Wire-cable-/281057554926?pt=LH_DefaultDomain_0&hash=item417055f1ee

    Female 14-50 50 amp receptacle on Amazon:

    http://www.amazon.com/gp/product/B00192QB9M/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1

    Male 6-50 50 amp plug on Amazon:

    http://www.amazon.com/Leviton-931-Angle-Grounding-Black/dp/B00004YUKC/ref=sr_1_6?ie=UTF8&qid=1410366403&sr=8-6&keywords=nema+6-50+plug




    http://www.teslamotorsclub.com/showthread.php/30302-Tesla-no-longer-selling-NEMA-6-50-Adapter

    - - - Updated - - -

    Nice diagram Cottonwood.

    - - - Updated - - -

    Nice diagram Cottonwood.
     
  14. Cosmacelf

    Cosmacelf Active Member

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    Nice find, Philba, that adapter will work for charging your Tesla just fine.
     
  15. FlatSix911

    FlatSix911 918 Hybrid

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  16. smsprague

    smsprague Member

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    The unicorn has been spotted
     
  17. Franko30

    Franko30 Member

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    Hi from Germany. Interesting tidbit: Wikipedia says that the 6-50 was/is common on farms for silo unloaders and that manufacturers of electric vehicle charging stations seem to use this connector with a one foot cord to connect the charging station to the grid.

    Live and learn: The plug varieties in North America seem endless. I'm glad every day that our 400 V 3-phase grid that goes into each house enables Up to 43 kW 3-phase charging with 22 kW installations being the most common. And only thanks to some very active Roadster drivers from Germany we have a Model S that has 3-phase chargers in the European Version.

    Cheers Frank
     
  18. Cosmacelf

    Cosmacelf Active Member

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    Does every house get 400v 3 phase?
     
  19. Franko30

    Franko30 Member

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    Yes, the local low voltage distribution networks run on 400 V 3-phase. This is then split up into 230 V/16 A one phase circuits for all the household appliances, except stovetops that run on 400 V 3-phase as well as the CEE red 400 V 16/32/63 A 3-phase sockets/circuits for heavy machinery (for instance circular saws) and charging equipment (so called wallboxes).

    For instance at my house: I have a 3-phase 400 V 16 A (11 kW) outlet in one garage and a 3-phase 400 V 32 A (22 kW) outlet in the other. In the latter, my Model S (and also our Renault ZOE) can charge with 22 kW, utilizing a mode 3, Type2 plug "wallbox". Throughout the house we only use 230 V/16 A sockets for household appliances.

    I'd really have liked to post Wikipedia links, but the German and English pages for Electric Power Transmission have completely different contents covering different systems.

    Frank
     

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