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WARNING: Extension Cords

Discussion in 'Prime Plug-in Charging' started by Rob43, Oct 15, 2019.

  1. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    I agree, yet still have advice I give.

    Owners ARE going to use extension cords to get electricity from their outlet to their car. I can give advice to make this dangerous link LESS dangerous, and I do.

    Use just one cord, use the biggest gauge of copper wire you can buy. (smaller number)
     
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  2. CharlesH

    CharlesH CA HOV Decal #5 on former PiP

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    Yes, the warning is mainly from the lawyers, not the engineers. They need to put in that verbiage so that some dummy doesn't injure themselves or burn down their house by using an inadequate cord, and sue Toyota for not warning them. So rather than specifying the safe way to use extension cords, they just say "don't do it, and don't blame us if you ignore our prohibition".

    EDIT: Elektroingenieur has pointed out good technical reasons for the prohibition of extension cords. See next post.
     
    #22 CharlesH, Dec 22, 2019
    Last edited: Dec 23, 2019
  3. Elektroingenieur

    Elektroingenieur Senior Member

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  4. Rob43

    Rob43 Senior Member

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    Like I've been advocating from post #1....

    Use Common Sense & A High Quality Thick AWG Pure Copper Extension Cord Only When Needed.



    Rob43
     
  5. CharlesH

    CharlesH CA HOV Decal #5 on former PiP

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  6. m8547

    m8547 Senior Member

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    Literally no other device I can think of has a temperature sensor in the plug, including things like space heaters that are designed to run at relatively high current for a long period of time. As long as the receptacle is in good condition a temperature sensor in the plug should not be necessary. If you expect to plug in and unplug the EVSE everyday then a heavy duty or hospital grade receptacle would be a good idea.
     
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  7. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    I think this is similar to the spark plugs where the engineers say: We want you to replace them every 120,000 miles but if you are in a CARB state we are forced to say they will last 150,000 miles by law.

    That 15 amp plug is not what they want at the end of their cable, it is just the only plug most Americans will ever use.
     
  8. fuzzy1

    fuzzy1 Senior Member

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    Don't forget how many homes burn and people die from problems with those high current space heaters and the outlets feeding them. The numbers are not insignificant, more than enough for the legal departments of deep pocket targets to be concerned about.
     
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  9. Rob43

    Rob43 Senior Member

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    Yes, this true and really should be given thought when adding an extension cord into the mix.

    ***********************************************

    So I'll say it again:

    Use Common Sense & A High Quality Thick AWG Pure Copper Extension Cord Only When Needed.



    Rob43
     
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  10. MarkOlin

    MarkOlin Member

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    I'm having a hard time finding a "copper" 10 ga (or 12 ga)., 10 ft extension cord. I found one on amazon "lifesupplyusa" but does not specify if its pure copper.
    is 15 amp sufficient? or should it be rated for 20 amps?
     
  11. mveras1972

    mveras1972 Member

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    I spent a couple of months using two 15A outdoor extension cords attached to each other. I needed 75 feet to connect my Prime to the nearest outlet. Never had an issue. They only got slightly warm near the connectors. If you know what you’re doing, you should be fine. I ran the cords every day to charge the Prime until I was able to install a 240V outdoor outlet in August and got Rob43 to make me an adapter. No more extensions needed and I charge my Prime in half the time. No issues whatsoever.


    iPhone ?
     
  12. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    A NEMA 5-20 Amp outlet looks different and is MUCH rarer. NEMA 5-15 amp outlets are everywhere.

    [​IMG]
    Your cord from Toyota is only a NEMA 5-15, so the rest of the circuit can be as well. We are over building, to reduce voltage drop and to keep the cord cool. No one wants to be 'that guy' who helped you burn down your house.
     
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  13. Rob43

    Rob43 Senior Member

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    The "LifesupplyUSA" extension cord is a CCA (copper clad aluminum) extension cord. Here's a screen shot of when I entered the word "copper" in the "have a question" section. Also when you click on the user pictures, most of them show a burned up plug with black charring. This brand should be avoided.

    www.amazon.com/dp/B01M0TIBWG/?tag=priuschatcom-20&th=1


    Rob43

    Screenshot 2019-12-25 at 12.52.35 AM.png

    Screenshot 2019-12-25 at 2.03.54 AM - Edited.png
     
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  14. m8547

    m8547 Senior Member

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    Lowe's has a 15 footer but I'm not 100% sure it's copper. I own one and it's fine.
    https://www.lowes.com/pd/Utilitech-Pro-15-ft-12-Gauge-3-Prong-Outdoor-Medium-Duty-Lighted-Extension-Cord/3191739

    For shorter ones, you can look at industrial suppliers like McMaster Carr. For example:
    Extension Cords, 10 Feet Long, Blue with Red Stripe
    McMaster-Carr
    FYI, their shipping is a little expensive, likely $10-15 for something this size, and they don't tell you ahead of time.

    I assume anything from McMaster is copper, but you could ask their support to be sure. Aluminum is a poor material for a flexible cord, so I'd only expect it from Amazon "fake" brands. McMaster pretty much only sells the highest quality items (unless you hey specify "economy" or something like that), but they don't say upfront who makes it.

    In my opinion 10 gauge is seriously overkill for 12A at less than 25 feet. 12 gauge is already a step up from the typical 14 gauge.
     
  15. Chazman62

    Chazman62 Member

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    I've been using a 12-gauge 10-ft long extension cord for 2 months now and it's been fine - no fire, no smoking, no melting, no burning smell no spark and no temperature rise that I could detect with my hand.
     
  16. Rob43

    Rob43 Senior Member

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    The problem is the pre-made ends, they use a Very thin amount of material, or they use a lower grade silver colored metal. Most likely any failure will come from one of the ends.

    Last: I really hope your extension cord is Not made by LifesupplyUSA, their extension cord is CCA & very poor quality.


    Rob43

    1742-d89d3730-0580-4cfd-b89a-d62f2e90f73c_-_Edited.png
     
    #36 Rob43, Jan 16, 2020
    Last edited: Jan 16, 2020
  17. m8547

    m8547 Senior Member

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    A loose or corroded socket is a concern too. I think that is one of the reasons for temperature sensing in the EVSE plug and the warning against extension cords, as much as anything else. Plugging in frequently is likely to wear out a standard receptacle over time. And being in the garage or outside is likely to mean more moisture and more corrosion. Higher grade receptacles can withstand more use. It is a good idea to use an industrial or hospital grade receptacle if you plug and unplug the cord frequently. And code now requires weather resistant receptacles outside, which are made with more corrosion and weather resistant materials.

    Has anyone made a complete list of possible problems with extension cords? How about this:
    • Some cords are not rated for 15A, and that is not obvious to the average user
    • A coiled cord can overheat
    • Extension cords can be damaged by people walking on them, running them under a garage door, etc.
    • The plug and socket ends are probably cheaply made
    • People might string together too many extension cords with too thin of a wire gauge
    • The wall outlet could have a loose or corroded connection and overheat, and EVSE would not be able to sense that
    • The end of an extension cord usually sits on the ground where it might get wet. Not every outlet or cord has proper GFCI protection
    • Cords from Amazon might not be UL listed and might be made of inadequate materials.
     
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  18. Chazman62

    Chazman62 Member

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    Above are EXCELLENT tips!
     
  19. m8547

    m8547 Senior Member

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    This one switches the safety ground. It's not clear why.


    I don't know if the Toyota/Panasonic or ClipperCreek ones do.
     
  20. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    From Wikipedia: The live wires of public charging stations are always dead if the CP-PE (Protective Earth) circuit is open

    So not having ground continuity is a safety measure. It is always ground on the car side, when current is detected, the EVSE becomes live.