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Wall connector - Charge speed reduced

Discussion in 'Model X: Battery & Charging' started by masam, Sep 9, 2016.

  1. masam

    masam Member

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    I have a Tesla Wall connector (set to 72 amps) that I was using to charge a Model X P90D. The charge current was set to 72A. However after a short while (maybe a few minutes of charging), I got the "Charge speed reduced" message that you can see in the attached picture. The car is saying that it has detected an extension cord or faulty wiring. Has anyone else run into this issue ? The wall connector was installed by a licensed electrician.
    Thanks!

    hpwccharging.jpg
     
  2. randy1077

    randy1077 Model X60 Vin 180XX. Reverved 8/11/2016

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    Sounds like you have undersized wire causing a voltage drop. I would use 3AWG copper for 80 amp breaker.
     
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  3. masam

    masam Member

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    Thanks ! Looks like I'll have to get the electrician to come back and redo this.
     
  4. FlatSix911

    FlatSix911 918 Hybrid

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    In the interim, I would suggest lowering the charge rate to 64 amps to avoid any issues :cool:
     
  5. TexasEV

    TexasEV Active Member

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    Charging at 72A would require minimum 90A breaker, not 80A.
     
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  6. nuevodesi

    nuevodesi Member

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    That is correct. I just installed my wall charger for 72amp circuit with a 90amp breaker running #4/3 Copper. Check out the installation here.
     
  7. masam

    masam Member

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    Absolutely ! While I have a 100amp breaker, I must admit I don't know what gauge wire they put in. I also had a NEMA 14-50 put in, so that will be the workhorse for now
     
  8. ig_epower

    ig_epower Member

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    I don't mean to thread jack but I have a wall charger set on a 40A circuit. I don't have reduced charging message issues but I don't need the fast charging - is setting to 30A not reduce the load on my circuits and also perhaps reduce the stress on my battery help matters? I figure the electrical costs would be similar to going at 40A?
     
  9. TexasEV

    TexasEV Active Member

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    If you have a 40A circuit the most you can charge at is 32A. Setting it for 30A isn't really reducing anything. Regardless, reducing the charging rate from 40 to 30A doesn't reduce the stress on the car. It's designed for the higher rates. You don't have to baby it.
     
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  10. jbabb

    jbabb Member

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    The picture shows a voltage of 220V when pulling 72A. What voltage does it show when only drawing a few amps? If the voltage starts out higher and drops very much as the current ramps up, the car detects that condition resulting in the message you see.
    Have your electrician verify the gauge of the wire, and that all connections are tight. If the wiring is run a long distance, you may need a larger wire size to avoid the excess voltage drop.
     
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  11. rypalmer

    rypalmer Member

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    This. It's the voltage drop that matters.
     
  12. masam

    masam Member

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    I didn't pay attention to the voltage when the car was first plugged in. I just had the car for an overnight test drive, so I'll have to wait for my car to be delivered before I can re-test. But, as you mentioned, there's a good chance that the wire length is the culprit. The run from the panel to the wall connector is over 100 ft. (not by choice).
     
  13. TexasEV

    TexasEV Active Member

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    You've probably identified the problem, which may be remedied by heavier gauge wire.
     
  14. masam

    masam Member

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    Thought I'd post an update here - the circuit was required with #3 wire but the problem persists. I'm now wondering if the service line coming in to the house is the culprit. While I can charge at 62 amps without issues I'd rather use the full 72 amp for a faster charge.
     
  15. OlavA

    OlavA Member

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    For an 80' run I used #2 wire and get 238V at the car. In addition, I had the service increased to 200A into my house.

    If you charge off peak household hours do you get the same result?
     
  16. CaliX

    CaliX Member

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    I am in the same boat as you as mine drops down to 60 amp and I get the same message. My run is over 100' I have had it rechecked by another licensed electrician and Tesla checked all the logs on my X what they determined is it's the service coming into my house most likely the transformer. So I am now pressing my electric company to check the line and transformer.
     
  17. masam

    masam Member

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    Definitely in the same boat. My run is also over 100'. I've requested the electric company to check the lines coming into the house.
     
  18. masam

    masam Member

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    I tried charging during off peak hours and it didn't help. I already have 200 amp service, so at this point I'm hoping the electric company can help with this
     
  19. OlavA

    OlavA Member

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    View attachment 198642
    Probably a good idea.

    They can check the voltage across the meter and go back from there.

    I am getting a solid 241V from my meter.
     
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  20. CaliX

    CaliX Member

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    I have 400 amp coming into my house with a 200 sub going out to my garage. My electric company is coming out to install a monitoring system to check and see if there is a 8% fluctuation that tesla says they see.

    Call Charging installation inquiries or issues M-F 9-5:30 PM PST 650-681-6133 they have been very helpful and they continue to monitor my X and are giving me feedback. They say its the line and or the transformer.
     
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