50 ft extension cord - 14 gauge - Is it safe to use?

Discussion in 'Prime Main Forum (2017-Current)' started by Sid786, Sep 20, 2017.

  1. Sid786

    Sid786 Active Member

    Joined:
    May 2, 2017
    180
    130
    0
    Location:
    Cherry Hill, NJ
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    Is it safe to use a 50ft extension cable with 14 gauge for connecting to charge Prius Prime and connecting to charging cable to charge at home with 110v?
     
  2. priuscatprimeguy

    priuscatprimeguy Senior Member

    Joined:
    Nov 1, 2016
    2,727
    2,620
    0
    Location:
    Farmington Hills, Michigan
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    dono, will it handle at least 15 amps continuous current? if so then yes. that's 1650 watts
     
  3. HPrimeAdvanced

    HPrimeAdvanced Senior Member

    Joined:
    Mar 2, 2017
    2,294
    3,496
    0
    Location:
    Anaheim, CA
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Advanced
    I've used a 25 ft 12 Gauge for over 6 years (mostly with 2012 PIP), and it works fine. The TOTAL length is 50 ft;
    I wouldn't go longer.

    .
     
    priuscatprimeguy likes this.
  4. Washingtonian

    Washingtonian Active Member

    Joined:
    May 26, 2017
    387
    367
    0
    Location:
    Western Washington
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Advanced
    You would be safer with a 12 gauge extension cord. I wouldn't recommend using a 50 foot 14 gauge cord for charging your Prius.
     
  5. Lee Jay

    Lee Jay Senior Member

    Joined:
    Jun 25, 2009
    4,731
    3,494
    0
    Location:
    Westminster, Colorado
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    It's safe, under some conditions.

    Basically the problem is heat.

    If the wire is kept stretched out and in a reasonably cool environment, it's probably safe. It should be noted that the EVSE the car came with uses a 14 gauge cable. I've been using it coiled and it's been fine, but it's 105°C rated cable, while many extension cords are 85°C or even 75°C rated. Because of that difference, I generally recommend 12 gauge if you're going to use an extension cord, especially if it's going to be either in the sun or in a hot environment like an uninsulated garage in the summer sun.
     
  6. Skylis A

    Skylis A Senior Member

    Joined:
    May 20, 2013
    1,141
    852
    0
    Location:
    Maine
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    What if you dropped the current to 8 amps? There is a setting in Charge Settings instead of maximum current you can use 8 Amps, so 110 V x 8 A = 880 Watts. This would also mean 10 hours of charging I would think, but so what, you're charging it overnight anyway, right?
     
    arthur92710 and Oniki like this.
  7. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    83,789
    36,678
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    if you do go with it, check the plugs at both ends frequently, they tend to heat up faster the the cable itself.
     
  8. priuscatprimeguy

    priuscatprimeguy Senior Member

    Joined:
    Nov 1, 2016
    2,727
    2,620
    0
    Location:
    Farmington Hills, Michigan
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    yup, that would work:D
     
  9. PT Guy

    PT Guy Active Member

    Joined:
    Nov 23, 2016
    651
    447
    0
    Location:
    Washington, the state
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Advanced
    Very important point. Start with the receptacle. If it has a lot of years or a lot of use, replace it. Buy the $2.59 receptacle, not the 59¢ one. You want good, tight contacts inside the receptacle with both the wires and the plug blades. Be sure the plug blades are clean and in good condition, not bent. Do touch all the parts occasionally. If you feel warmth, upgrade the parts.
     
  10. priuscatprimeguy

    priuscatprimeguy Senior Member

    Joined:
    Nov 1, 2016
    2,727
    2,620
    0
    Location:
    Farmington Hills, Michigan
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    here's a 12 Gauge 50 foot

     
    Sid786 likes this.
  11. David Beale

    David Beale Senior Member

    Joined:
    Jul 24, 2006
    5,963
    1,933
    0
    Location:
    Edmonton Alberta
    Vehicle:
    2012 Prius
    I build my own and they last. I use #12 and #10 gauge "cabtire" cable. They are very expensive. The one I made to power the garage before I installed buried cable cost me $150. But it doesn't heat up, even when block heaters are plugged into it. The old type "immersion" heaters, that actually heat the block, that draw more than 900 W. The one in my old Subaru was 1700W. The heater blew warm air as soon as the car was started!

    Do consider the outlet you are plugging into uses 14 gauge wire from the breaker box and could be 50 feet long. As stated above, as long as it's not left coiled up the heat shouldn't cause any problems, though that from someone living where 30C is "hot". ;)
     
    HPrimeAdvanced and jerrymildred like this.
  12. Sid786

    Sid786 Active Member

    Joined:
    May 2, 2017
    180
    130
    0
    Location:
    Cherry Hill, NJ
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    Thank you all for the response.

    Yes, I am only looking for overnight charging and if there is a setting, as you mentioned, to drop the amps to 8A, then I can drop it to 8A and let it charge safely, even if it takes longer.

    I am in an apartment building and I can use the Air Conditioner plug, which I am assuming will handle this charge. I am estimating that a 50 ft cable will do the job. During the winter time, there is no use of AC, so this plug will be available for charging.

    A/C rating is 10000 BTU and it says 9.8 amps with 115 V, so hopefully reducing my charging to 8 amps should be fine.

    I just want to avoid any short-circuit, damage to the car or even fire hazard.

    Maybe I will test this for few hours only at first.
     
  13. Lee Jay

    Lee Jay Senior Member

    Joined:
    Jun 25, 2009
    4,731
    3,494
    0
    Location:
    Westminster, Colorado
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    For reference, a hair dryer draws about 15A, a vacuum cleaner draws about 12A and a big garbage disposal draws about 8A. The difference here is the length of time - hours instead of minutes.

    I've been charging my Prime off a 15A circuit with a 35 foot 12awg extension cord tied to the loosely coiled up EVSE. The thing that gets the warmest is the EVSE cord near the velcro band tying it together and that's only about 15°C above ambient.
     
  14. Since2002

    Since2002 Senior Lurker

    Joined:
    Nov 12, 2011
    936
    1,091
    0
    Location:
    Duluth, GA
    Vehicle:
    2006 Prius
    Model:
    N/A
    You could check the temperature by feel which might be good enough but I would think using an infrared thermometer would be even better, especially to detect if the temperature of the cable is rising which would be hard to do by feel. I would think an inexpensive thermometer would be accurate enough.

     
    priuscatprimeguy likes this.
  15. bps

    bps Active Member

    Joined:
    Jun 27, 2006
    298
    112
    0
    Location:
    Rhode Island
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    Thanks! I just ordered one. It looks like a handy tool to have.
     
  16. Oniki

    Oniki Active Member

    Joined:
    Jun 10, 2017
    652
    493
    0
    Location:
    Colorado
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Plus
    Any chance of someone tripping on the cord ?
     
    HPrimeAdvanced likes this.
  17. David Beale

    David Beale Senior Member

    Joined:
    Jul 24, 2006
    5,963
    1,933
    0
    Location:
    Edmonton Alberta
    Vehicle:
    2012 Prius
    The circuit you intend to use is a 15 Amp one. They usually dedicate a breaker for the air conditioner, as they tend to operate near max current when starting up. You should be able to charge at the higher rate. Do note, if there is voltage drop in the extension cord the current may go up to compensate. I would purchase a 12 gauge cord.

    Oh, and yes, the tripping hazard would be greater than the electrical hazard. ;)
     
    arthur92710 and HPrimeAdvanced like this.
  18. William Redoubt

    William Redoubt Senior Member

    Joined:
    Feb 13, 2016
    1,192
    1,126
    1
    Location:
    Coronado Island, California
    Vehicle:
    2016 Prius
    Model:
    Two
    At 50 feet you should be using a No. 12 wire size. Don't cheap out on this. Too light of gauge is a fire hazard. I would use an outdoor cord, and build it myself with the proper HD ends.
     
    HPrimeAdvanced and Mark57 like this.
  19. Sid786

    Sid786 Active Member

    Joined:
    May 2, 2017
    180
    130
    0
    Location:
    Cherry Hill, NJ
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    Is there a way to test the amps capacity of a circuit. For example,can I use a multimeter and plug it into my Air Conditioner plug to tell me the max amps I can draw from this circuit.
     
  20. GregoryG

    GregoryG Junior Member

    Joined:
    May 4, 2016
    8
    2
    0
    Location:
    Forest Grove, OR
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    As previously touched on, a thicker cord will reduce electrical resistance and therefore heat. It takes energy to produce that heat, which means that a thicker cord will save you a bit of energy.

    For example, the American_wire_gauge Wikipedia article gives the resistance in milli-ohms per foot for various wire gauges.
    • 14 gauge: Resistance = 2.252mOhm/foot * 50 feet = .113 ohms. Voltage drop = (.113ohms*15A) = 1.69V Power used = (1.69V*15A) = 25.3 watts
    • 12 gauge: Resistance = 1.588mOhm/foot * 50 feet = .079 ohms. Voltage drop = (.079ohms*15A) = 1.19V. Power used = (1.19V*15A) = 17.9 watts
    So, you can save about 7 watts during charging by using the thicker cord.
     
Loading...