TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker or making a Paypal contribution here: paypal.me/SupportTMC

Warm Breaker Normal for 14-50

Discussion in 'North America' started by ddimit, May 4, 2015.

  1. ddimit

    ddimit Member

    Joined:
    Aug 21, 2013
    Messages:
    258
    Location:
    Sacramento, California, United States
    New 85D owner.

    I self installed my own 14-50 in my garage. I do have pretty extensive electrical experience but not not an electrician by trade.

    I Noticed the the breaker seem warmer than i think it should be on charging.

    Some Background

    Garage is fed from main house panel on 70 amp breaker with #4 about a 70 ft run to Garage.

    Garage has Sub panel feeding plugs and lights. (minimal loads)

    14-50 is 2 feet from Sub and is fed with #6

    Sub is Cutler-Hammer panel with Correct Eaton Breaker via documentation on Sub Panel.

    I Dialed down current to 30 amps, Breaker is still running warm but not as warm as 40 amp setting.

    Car reports voltage 243-245 on avg with no drops or throttling back by the car.

    Could it be a bad breaker or is this considered normal behavior?
     
  2. mknox

    mknox Well-Known Member

    Joined:
    Aug 7, 2012
    Messages:
    8,570
    Location:
    Toronto, ON
    EVs present a "continuous load" which is not common among most electrical loads. Most appliances, heaters and such will cycle on and off and therefore will not generate as much heat at connection points in the circuit. That's why it's important to use the proper sized wiring, breakers and outlets (as it appears you have) and to make sure all connections are tight and secure.

    In my experience, it is normal for the breaker to get warm, but certainly not hot. I will notice the same on my water heater and a/c breakers when either is running for a prolonged period.
     
  3. Tommy

    Tommy Member

    Joined:
    Mar 3, 2010
    Messages:
    880
    Location:
    The great OC
    Did a self install myself; some things to consider: You didn't mention the breaker rating and on the off chance the breaker is underrated please verify the breaker is a 50 amp breaker. There is a torque tightening specification for the breaker terminals to be tightened to; verify the terminals on the breaker are at the correct torque. Lastly, verify the wires leading into the breaker are not over bent. Sometimes in our zeal to make a "neat" appearance, wires are bent too sharply and that can cause a wire to run hot and heat up the breaker.

    Some description regarding why you feel it is too warm would help; Is it similar to touching a 15w light bulb (warm but the hand can stay on the bulb) or a 50w light bulb (very warm, some discomfort) or a 75-100w bulb ( not able to touch for more than a few seconds). You may have a better description, just trying to get an idea why you think it may be to warm.
     
  4. ddimit

    ddimit Member

    Joined:
    Aug 21, 2013
    Messages:
    258
    Location:
    Sacramento, California, United States

    Yes confirmed 50 amp breaker. its warm but not hot. maybe its just unusual to me to feel a breaker get warm like that granted I don't have anything doing a continuous draw at that amperage. and no sharp bends at all! I have seen sharper bend in HWPC's
     
  5. qwk

    qwk Model S P2681

    Joined:
    Dec 19, 2008
    Messages:
    2,817
    Warm is normal, hot is not.
     
  6. FlasherZ

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

    Joined:
    Jun 21, 2012
    Messages:
    7,019
    I concur - warm to the touch is just fine, but hot is not good.
     
  7. tga

    tga Active Member

    Joined:
    Apr 8, 2014
    Messages:
    2,218
    Location:
    New Hampshire
    For comparison, I took some measurements with a non-contact IR thermometer. In my basement (63 deg ambient):

    Washing machine - 67 deg (at end of the final spin cycle)
    Dryer - 81 deg (well into second load of drying)
    Solar system - After an hour plus of peak production, putting ~32A through a 40A breaker - ~105 deg

    The 105 degree breaker was noticeably warm, but not disturbingly so.
     

Share This Page