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Wiring scheme for Universal Mobile Connector

Discussion in 'Roadster: Technical' started by delavandaag, Apr 3, 2015.

  1. delavandaag

    delavandaag Member

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    As I am facing problems with charging on 32A or higher (240V) with my Universal Mobile Connector - sometimes the voltage drops below the threshold that is accepted by the Roadster or the UMC - I called the electrician who installed the UMC to come and verify what is wrong. He says the capacity of the electrical system is more than sufficient to charge at 32A but suspects that he did not install the wiring correct. The Roadster only charges on one leg where three legs are available. I guess this explains why the charge cable gets warm (except for the last part from the UMC itself to the Roadster which stays cool). The electrician has asked me to provide him with a wiring scheme.

    Tesla once had the wiring scheme available on its website. The link is still there but gives a 404-error (not available). I called Tesla two weeks ago but they still have not managed to provide me with the scheme. Does anyone have a copy of this scheme? If it matters, the UMC is a European (Dutch) version.
     
  2. widodh

    widodh Model S R231 EU

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    The Roadster charges on 1-phase. The red connector is probably wired to L1 only. So make sure the wiring for L1 is able to handle 32A. That should be a 6mm2 wire.

    If you lower the Amperage to let's say 20A, does it charge then?
     
  3. delavandaag

    delavandaag Member

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    Yes, it charges fine on lower settings in Amps. 16A gives no problems. 24A sometimes gives problems, but not if the ambient temp is low. If it freezes I can load on 32A.

    Would it not be possible to load-balance the current over three legs?
     
  4. widodh

    widodh Model S R231 EU

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    No, you can't balance. Your main problem is probably the wires which aren't big enough. It is probably a 2,5mm2 wire which is suited for up to 20A. If it's very cold 32A might work indeed.
     
  5. delavandaag

    delavandaag Member

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    Oh, well, I might have a problem then. Or my electrician, who did not wire it correctly. And actually, the 32A charging worked for one and a half year without any problems. The problems started last summer with ambient temps during night of +20C. I more or less forgot about it when it went colder. The problems have now returned and are occurring with temps of 10C or lower. Could that be caused by too much stress on that one leg of the cable because too high currents have gone through it? If that is the case the cable has to be replaced, which will be costly for a cable of approximately 40 meters.

    And thanks widodh, for your replies.
     
  6. widodh

    widodh Model S R231 EU

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    Yes, that is the main problem. When the ground/earth is cold is cools the cable. But when it gets warmer the resistance in the cable goes up.

    When that happens the voltage drops and the Roadster will stop charging.

    Could you make a picture of the label or look it up? It should say something like: 5G2.5 or 3G3.5 or maybe 5G4, etc.

    That tells you the wire size.
     
  7. delavandaag

    delavandaag Member

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    #7 delavandaag, Apr 3, 2015
    Last edited: Apr 4, 2015
    This is the adapter. 4P5W, is that the code? If so, what does it mean?

    image.jpg
     
  8. gregd

    gregd Member

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    This sounds to me like one or more of the wiring connections (screws) is loose. I'd suggest they get tightened (with the mains power OFF!!!) and see if it makes a difference. Wires surely do change their resistance with temperature, but not so much as a loose connection can. They're mechanical as well as electrical, and the mechanics part expand & contract with temperature, affecting how well the wiring makes contact.
     
  9. delavandaag

    delavandaag Member

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    Which connections do you mean? Inside of the UMC or adapter? The electrician already checked the other connections (in the fusebox and around the mains power switch).
     
  10. gregd

    gregd Member

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    I was referring to the electrical connections in the fuse box, through to the socket where the UMC is plugged in, including any splices in between. If they've already been tightened by the electrician, then that's not the problem.

    Just curious, what voltage does the car think it's getting? It's at the bottom of the VDS while charging. My 240V (nominal) connection varies down to 236V or so, depending on the load and other factors I haven't discovered, but no problems. I made my own 2-socket, 10-foot, "extension cord" using a replacement dryer cord and some 12-guage house wire, so I can plug both the dryer and car into the same plug (but not run both at the same time).
     
  11. delavandaag

    delavandaag Member

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    I have seen it as low as 213V.
     
  12. gregd

    gregd Member

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    Yeah, that sure sounds like a bad connection, presuming that it was a lot closer to 240v before. And a bit scary. If you're dropping 27 volts at 30 amps, somewhere something is burning (no pun intended) over 800 watts, and should be getting noticably warm.

    Are you sure the mains supply is 240v, or is that sagging too?
     
  13. Panicopticon

    Panicopticon Member

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    #13 Panicopticon, Apr 5, 2015
    Last edited: Apr 5, 2015
    delavandaag is in Europe. Would I be correct in guessing that means you're charging at 220 single phase? If thats the case, its only a 7V drop, which while not good isn't horrible.

    You said there was a link to the diagram on the site, but that it was 404'ed, do you have the link handy? I may be able to dig up the doc.
     
  14. delavandaag

    delavandaag Member

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    It is my understanding that my connection at home is a three phase connection. And the Roadster can only be charged at single phase, according to widodh earlier in this thread.

    The dead link on the Dutch website is: http://my.teslamotors.com/nl_NL/roadster/charging/universal-mobile-connector, on the international website: http://my.teslamotors.com/roadster/charging/universal-mobile-connector (it is the 'Information Sheet'-link on the right side of these pages). It would really be helpful if I can show my electrician the official diagram.
     
  15. Panicopticon

    Panicopticon Member

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    #15 Panicopticon, Apr 6, 2015
    Last edited: Apr 6, 2015
  16. delavandaag

    delavandaag Member

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    After having Tesla reminded for several times that I really need the guide for the UMC, I still have not received a clear response. I suspect that Tesla is not willing to give me a copy as a ranger told me yesterday that the UMC does not - much to my surprise - meet the European regulations. When I told him that it was nevertheless sold to me in 2012, I got a polite smile but no (other) reaction.

    Anyhow, in the meantime I have determined that I have two problems related to charging. The first - as set out earlier in this thread - is the incorrect wiring from the main panel to the UMC. The second is the 32A adapter that came with the UMC. It has a slight wobbly/not perfect connection causing resistance/heat and some coloring, probably caused by heat/warming, is visible within the adapter. Both cause voltage dropping and charging at higher Amps gives problems; the charging is cut off often, especially when ambient temps are at 25C plus. I would ask the experts among us to verify my followings plans on any danger - for the Roadster as well as for anyone or anything else.

    INCORRECT WIRING: the UMC is connected to a 32A three phase system (able to deliver 230V, not 240V as I mentioned earlier). The UMC, as far as I have been able to check, does not accept/cannot be connected to all three legs of the 3 phases. The wire from the main panel to the UMC has 5 conductors, each 4mm sq. I need some 25 to 30 meters to bridge with the wiring, which runs partly through a cellar and partly under the ground. The cable is especially designed/suitable for use in the ground.
    My plan is to use two pairs of conductors for the two legs of electricity (by disconnecting two of the three phase legs in the main panel) and one for the ground connection. Is there any risk in doing so? Should I take special measures in pairing the conductors? I do not mean any risks in terms of shutting off the power when the pairing will be done or connecting the correct conductors at the correct spot, but in terms of any resistance/heat that may be caused when 230V at 32A flows through paired conductors and how to limit that, if possible. Should the conductors be twisted in each other, or is it better to not do that? Or would 4mm sq. per conductor be sufficient for the 25 to 30 meters and should I not pair the conductors and leave the wiring as it is?
    Another question: is there any risk in only taking the load from one leg of a three phase connection? I have done that for 2.5 years now, but without realising this.
    BTW if I will proceed with this, these operations will not be done by myself but by an electrician. So do not worry.

    THE 32A ADAPTER: the plan is to remove it and connect the end of the cable that is connected to the adapter - nearest to the UMC - directly in the plug (CEE male 5 polig 6H 32A IP67 stekker 380-415VAC). The question I have here, is whether the purple wire for the pilot signal should be connected (indeed, as suggested in a couple of other threads on TMC) to the ground cable? And is there any risk or negative consequences in having the small device that is connected to the purple wire put in the plug instead of in the adapter? This device is tied to a piece of plastic that forms part of the inner side of the adapter with two tie wraps. The plug in which I plan to put it in, has nothing in it to tie it to, except for the conductors. Is it safe to tie it to the ground cable, as much as possible away for the other conductors?

    Any help/reaction is appreciated.
     
  17. ravng

    ravng Member

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    Your car is a significant load on your electric system and not to be played around with. There is a lot of laws and regulation, and specific requirements for EV charging in europe, and there is a good reason for this.
    You have bought an expencive car, please don't get cheap when it comes to the charging solution that might burn down your house.

    Some points to keep in mind:
    1) You need a UMC or other EVSE (Electric Vechile supply equiptment) to charge above 13A. If you ground the pilot you get a maximum of 13A. Also european rules regarding EV charging (iec 61851) requires different safety measures you will not get if skipping an evse/umc.
    2) 4mm is not enought for 32A, at least not in this country. 6 or 10mm is reguired, depending on where the cable is located (in isolated wall, ground etc).
    3) You are not allowed to combine pairs to get more current thru, there is good reasons for this!


    I would get a certificed electrician to replace the cables with new onces, and ensure that you have the required earth protection installed.
    I would also replace the UMC with a better permanent EVSE unit, and keep the UMC for road trips.





     

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