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Strange burning smell coming during charging and look....

Discussion in 'Model S: Battery & Charging' started by jefflieb, Jul 9, 2015.

  1. jefflieb

    jefflieb Member

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    over a few day period I have had a strong burning smell and look what is going on

    IMG_3311.JPG IMG_3312.JPG

    Educate me...... why? how?

    I have replace this with my long extension
     
  2. wycolo

    wycolo Active Member

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    These are not Tesla parts and Tesla advises against using extension cords to charge their cars. Was the burning smell not a clue to maybe feel the plugs/sockets for unusual heat build-up? It is usually a good move to scrape the prongs (and their counterparts) down to bright copper before pressing back into service. They can get rather groady sitting around in storage. Time for an electrician?
    --
     
  3. scaesare

    scaesare Active Member

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    Several possible causes:

    - Bad weld/connection within the extension cord causing heat

    - Bad weld/connection within the plug head causing heat

    - Bad contact mating surfaces causing heat

    But I have to ask what we are seeing? That's not a UMC head, nor a wall outlet... are you plugging two extension cords back to back? Or is that both ends of the same cord, and it got hot on both ends?
     
  4. jefflieb

    jefflieb Member

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    its two extension cords NEMA 14-50 one Camco (yellow) 15ft and one 4 ft to UMC
    my garage was built in 1929 for a "Model T" and is tight on all sides with BIG BERTHA inside.
    I leave her out seasonally so I do not have to do the squeeze play out of the car and all the other risks of damage
    My plug location was short sighted 18 moths ago....Who knew about all the nuances of plug access...I do NOW!
     
  5. scaesare

    scaesare Active Member

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    Given that Tesla does not support even one extension cord in usage, I suspect 2 back-to-back for sustained high-current utilization is simply asking for trouble.
     
  6. Electricfan

    Electricfan Member

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    Were you charging at 40 amps? If you have to continue using extension cords you might drop the current down. Also, feel the connectors daily to check for heat. They should be warm/hot, but not burning hot. You can also build your own extension cord with no.8 wire, or even no. 6. (thinking here about 40 amps, you'll need more wire if you have dual chargers, etc) You should also disconnect extension cords daily to check for burning or discoloration. Tesla has to recommend against extension cords, but we live in the real world (with garages built in 1929 sometimes) so they're a part of life with an electric car.
     
  7. TexasEV

    TexasEV Active Member

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    If you have no other option than to use an extension cord, evseadapters.com has a 20 ft. one which would be better than linking a 15 ft. cord and 4 ft. cord together:
    Heavy-duty NEMA 14-50 extension cord for Tesla, 20 ft.

    Also Camco has a 30 ft. cord like the 15 ft. one you had.
     
  8. AmpedRealtor

    AmpedRealtor Active Member

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    Camco sells a 30 foot version of this extension cord. I used it successfully to charge at 20A from a dryer outlet. I haven't used it at 40A.
     
  9. AB4EJ

    AB4EJ Member

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    It is great that you didn't have a house fire due to this. Think about it: charging at 245V, 40A = 9800 watts - this is like running your kitchen range with all burners on including top and bottom in the stove - for hours on end. If you have to use an extension cord due to the 1929 garage, you need to keep a close eye on it. If it was me, I would install a smoke detector in the area.
     
  10. Gizmotoy

    Gizmotoy Active Member

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    Extension cords are useful in a pinch, but using one at home is a bit sketchy.

    There's a company that modifies Tesla UMCs with longer cables. Then you don't need the extension cable at all. I can't remember the name, though. Anyone?
     
  11. linkster

    linkster Member

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    #11 linkster, Jul 9, 2015
    Last edited: Jul 9, 2015
    Tony Williams of Quickchargepower can stretch your Tesla UMC up to 50'. I keep the "50" in the car and deploy the standard issue UMC (permanently docked) on my home 14-30 for the last 51K miles.

    Tesla UMC extension


    I prefer no extension or only (1) if necessary and I rarely "redline" (max draw) any of my charging equipment.



    image.jpg
     
  12. kennybobby

    kennybobby Member

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    It wasn't a cable failure, it was the junction in the yellow connector. If you open it up you will find that the spring clip terminal that is supposed to contact and hold the blade has opened up such that little or no contact with the blade was possible. But the 40A current at 240vac will arc and spark across the gap--the carbon black on the blade is the residue of an arcing contact. The heat generated by the arcing in the high-resistance junction caused the spring terminal to open even wider, and the resistance increases causing more heat and the cycle repeats, aka thermal runaway. Poor metallurgy and manufacturing knowledge resulting in a third world product.
     
  13. FlasherZ

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

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    NEC 625.17(C) limits the overall cord and cable length to 25 ft unless the product is listed with an equipped cable management system, so you may experience liability or insurance issues if there's an issue. You're likely not to have an issue, and it's relatively safe (because it's protected by all the UMC's protection circuits), but something to keep in mind if something happens.
     
  14. jefflieb

    jefflieb Member

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    This explanation is just what I was curious about, THX

     
  15. EVenthusiast

    EVenthusiast Member

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    There are several threads now about EVSE (related) components smoking/catching fire, and in some cases, not even getting noticed until after the event.

    With more and more households getting an electric vehicle, chances are this is going to become more of an issue (too many people not understanding limitations/safety and/or stuck with old house wiring).

    Is anyone aware of a product which allows you to easily monitor the temperatures at the plugs/vehicle?

    Would a ceiling-mounted smoke/heat detector placed right above the charge port location detect anything?

    Should I just build it myself using an Arduino and some thermistor probes wrapped in certain spots (or even go the FLIR route)?

    I'm happy OP is OK, but it looks like he got really lucky.
     
  16. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    Non-reversible temperature labels are the easiest way.
     
  17. bp1000

    bp1000 Member

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    Do you guys not have circuit breakers in north America?

    The circuit should have tripped to prevent this?

    You should only ever charge via correctly spec-d outlets and cables. Never use extension cords and here in the U.K. A 13amp standard plug is too close to the limit so the advice is to tune it down to 10amp. old wiring or bad connection is a fire hazard.

    Im really surprised you didn't burn down your garage.
     
  18. tga

    tga Active Member

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    The DA20's I've flown have one of these on the main spar, visible from the cockpit, to make sure it has not overheated to the point of damaging the composites. Checking it is part of the pre-flight checklist.

    A standard breaker would not have tripped (no overcurrent). An AFCI breaker probably would have, but I've not seen double pole AFCI's >20A.
     
  19. Frank Mucus

    Frank Mucus Member

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    It's a secret society, all we axe is trust.
    My adapter burned in the same exact area and so did other ones when I looked it up. I didn't charge from an extension though but from the outlet itself. Everything checked out fine too.
     
  20. FlasherZ

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

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    That's what is called a high-resistance "glowing" connection, and likely wouldn't have tripped AFCI, either. AFCI's search for an arc signature. In this case, this is just a high current going through a high resistance connection.
     

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