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Anybody shave Neutral pin from Mobile kit NEMA 14-50 adapter?

Discussion in 'Model S: Battery & Charging' started by scottm, Oct 21, 2014.

  1. scottm

    scottm Active Member

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    Shaving off the Neutral pin from the NEMA 14-50 adapter in the mobile kit means that adapter would fit both NEMA 14-50 (50 AMP, stove) and NEMA 14-30 (30 AMP, driver) receptacles, should you come across either. Knowing the adapter is rated for the higher 14-50, it would easily handle the 14-30. You can adjust the charge rate on the touchscreen, so jack it down to 30 when you know you're plugged into the dryer outlet, jack it up to 50 if you're in a stove outlet.

    Anybody done this?

    Or maybe you can answer these questions, is there logic inside the adapter that:
    a) informs the mobile kit what adapter is fitted?
    b) senses for Neutral, faults if not present?

    If the kit needs to have Neutral present, then it would also be possible to not shave the Neutral pin off completely, but grind it "in half" (split lengthways) to fit both NEMA 14-30 and 14-50 receptacles (see pictures in wikipedia search "nema" to see what is meant).

    Anybody tried that?

    It would be a lot easier to take the pin off completely, if Neutral is not needed (sensed) by the mobile kit.
     
  2. ElSupreme

    ElSupreme Model S 03182

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    Don't do that!

    Buy a 14-30 adapter please. Tesla Gear Shop NEMA 14-30

    The 14-50 adapter tells the UMC that you can pull 40A. Trying to pull 40A through a 30A outlet is a accident waiting to happen. Sure you can always manually turn down the amperage, but just pay the $45 and buy another adapter.
     
    • Helpful x 1
  3. stevezzzz

    stevezzzz R;SigS;P85D;SigX

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    When I had my roadster I disassembled the plug end of the charging adapter and pushed out the neutral pin (I knew it wasn't used because it wasn't wired to anything) so I could do precisely what the OP asked. I never used it in the wild (I had a third party cable for that, with adapters) and needed to be able to plug into a 14-30 at the house. Once I programmed the R to use 24 amps at the house, it automatically dialed charging down to 24A at that location every time I plugged it in. By the time I got the S I had a different house with dedicated 50A circuits: I plugged in the modified 14-50 adapter and the R happily charged at 40A without intervention.

    Caveat: I don't know for a fact that the UMC's 14-50 adapter for the S doesn't make use of the neutral pin, but that's what I've heard second hand.
     
  4. scottm

    scottm Active Member

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    So the adapter does inform the UMC kit what adapter is attached.

    I wonder if it's like EV SAE scheme and just uses a resistor across couple of sense pins?

    It's not the $45, its the bulk of having more stuff toting around in the rear.. simplify simplify!
     
  5. ElSupreme

    ElSupreme Model S 03182

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    Yes the adapter plug (via a resistor) tells the UMC what the maximum amperage it can pull. Honestly you can put 2-3 extra adapters in the UMC bag easily. They don't take up any extra space, they all fit inside the coil.
     
  6. swegman

    swegman Member

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    Just get the 14-30 adapter and store it in the bag. The bag holds it without a problem. I have that, plus the 120/15A, 120/20A adapters plus a few others stored in the bag with no problems. What you suggest can be done, but as others have said, is an accident waiting to happen. Several people reported that the manually reduced charge level reverted back to a 40A charge level after a software update. Its just not worth the risk doing what you suggest.
     
  7. Gizmotoy

    Gizmotoy Active Member

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    IMO, it's probably worth the risk for recepticles Tesla doesn't officially support. I have a bag full of them that plug into the 14-50 I got from EVSE Adapters, but given Tesla makes a 14-30 I'd just use that. Especially if it'll see regular use instead of only "emergency" use.
     
  8. scottm

    scottm Active Member

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    #8 scottm, Oct 22, 2014
    Last edited: Oct 22, 2014
    I have Tesla HPWC in the garage and dual onboard charging, do all my charging there.

    I consider all the non-J1772 adapters to be a bunch of funny plugs needed for 'emergency use' only, in the wild / roadtrips when I come across a receptacle and I'm in dire need of a charge... I want power.. with high odds of things fitting together to get juice.

    Setting the onboard charge draw is only one safety factor, Tesla electronics are self regulating too. They step up draw gracefully and "feel" for voltage sag on the line, and will only draw current up to its set maximum so long as the power equation remains balanced and within its limits.

    Of course the car can do nothing about popping a breaker if I've set to draw 40A from a 30A breaker. But that's what breakers are for, another (final) level of protection. Resolution: reduce power draw and reset breaker and try again.

    I think my question has been addressed, but not conclusively, because nobody has tried it.

    Q: Can the neutral pin be removed from the mobile kit NEMA 14-50 adapter?
    A: Yes. The 14-50 adapter on the mobile kit makes no use of the neutral pin so it can be omitted without change to the charging function from a 14-50 receptacle.

    I think I might be the first person to try removing the pin. Of course, I'll actually test the theory first by removing the neutral line from the receptacle. And if that works, zip goes the pin. I'll update this thread when that happens. If someone else proves it in the meantime, post here and you'll save me the step of diddling with the receptacle. Thanks!
     
  9. Cottonwood

    Cottonwood Roadster#433, Model S#S37

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    You can remove the neutral pin from the 14-50 adapter and it will fit in either a 14-30 and 14-50 receptacle (this works because the neutral pin is not connected in the UMC, and the other three pins are the same size in the two plugs), but why do that when a 14-30 adapter is available from Tesla and will signal the correct charge current to the car? The risk is small, but the cost could be high. If something goes wrong that is not your fault, because you made a non-standard modification to Tesla equipment, you open yourself for insurance and warranty claims problems, just to save a few dollars.
     
  10. scottm

    scottm Active Member

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    I think all your sentiments have already been shared in this thread, looking for new information if you've got it!
     
  11. Incredulocious

    Incredulocious '11 LEAF –> '13 RAV4 EV

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    #11 Incredulocious, Oct 22, 2014
    Last edited: Oct 22, 2014
    I've done the opposite: cut the neutral pin off of the Tesla 14-30 adapter so it can be used in a 14-50 or 14-30 outlet. And yes, each adapter does identify itself in order to communicate the expected max safe amperage.

    I did this modification after having my first 14-50 adapter eventually overheat and partially melt (even on my new and properly installed 14-50 outlet), as others have experienced and reported here. I now have the replacement 14-50 adapter with the temperature fuse but I only use it when I really need the full 10 kWh rate, which is rare and *not* while I'm sleeping. Since the RAV4 EV does not have an option to specify a lower charge rate, I use this modified 14-30 adapter to keep the charge rate down for normal overnight charging. (This is a Tesla Universal Mobile Connector modified to use a standard J1772 plug, produced by Tony Williams' QuickChargePower.com.)

    As others have said, do NOT cut the pin off the 14-50 adapter as this is just asking for an accident: potentially drawing more amperage than a 14-30 circuit can safely supply, and who knows if the circuit breaker will work as intended.
     
  12. Cottonwood

    Cottonwood Roadster#433, Model S#S37

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    For my Roadster, I have an extension cord with several adapters; one is a 14-30/50 with the neutral pin removed. It works fine, and I have tested it in both kinds of outlets. In fact, if you buy an aftermarket plug, many of them are a single box for either a 14-30 or a 14-50 with a choice of pins to install for the configuration you want.

    I used the 14-30/50 adapter for my Roadster on a 14-30 outlet once, set the charge current to 24 Amps and popped the breaker. I found out that the dryer was a high efficiency European dryer on a 20 Amp breaker. After resetting the breaker and turning the charge current down to 16 Amps in the Roadster, it charged fine.

    I hope that helps.
     
  13. scottm

    scottm Active Member

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    I am still seeking a model S owner who can speak to the "works fine" with the UMC for that car... having no Neutral pin. Your Roadster experience sounds promising but is not conclusive, unless it uses the same UMC as model S (I don't know).
     
  14. linkster

    linkster Member

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    O.K. Yes, it works, the neutral pin on the Tesla UMC 14-50 and 14-30 is a dummy pin and not connected/recognized by the UMC or car. Like others have suggested, please deploy safe charging practices.
     

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