AC power cord getting hot

Discussion in 'Heating / Cooling Systems' started by djohnsn, Jul 8, 2013.

  1. djohnsn

    djohnsn New Member

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    I have been doing some repairs to a popup that I recently purchased (2004 Jayco Qwest) and noticed that the a/c power cord is getting pretty hot. It is a rooftop Coleman unit that seems to work fine otherwise. I don't know if it was installed by a previous owner or a dealer. The cord is plugged into a receptacle next to a sticker marked a/c use (under a bench/seat). It is hot enough that it would be uncomfortable to hold for more than a few seconds. It is only hot fairly near to the plug itself. Is this something that I should worry about? If so, any ideas about why it is getting hot?
     
  2. SUPERKSR

    SUPERKSR Member

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    Should NOT be that hot to the touch. Honestly, it shouldn't be noticably warm.
    Open that receptical and inspect it. Badly corroded, or loose connections pose a serious fire hazard, and you don't want that.
     
  3. Unstable_Tripod

    Unstable_Tripod Well, there's your problem!

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    Is the cord (or part of it) coiled up? This increases heating. If so, spread it out.
     
  4. Raycfe

    Raycfe Waterford Ct.

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    I would replace the parts involved. Removing the plug from the outlet and feel the plug and outlet, if they are cooler than the cord, update the cord.
     
  5. EV2

    EV2 Member

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    Good recommendations, and there is one more thing to check. Where is your power source and are you getting adequate voltage at the a/c plug? (At least 110 volts)
     
  6. jayco1997

    jayco1997 New Member

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    trace the recp. that the AC cord is plugged into back to the panel and check to see it it goes to its own circuit breaker and if so check the size of the breaker. also check the size of the wire coming off of the AC to make sure its the right size wire.
     
  7. djohnsn

    djohnsn New Member

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    Thanks for all the suggestions. I will let you know what I find out.
     
  8. Camp-N-Nuts

    Camp-N-Nuts KrustyKamper

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    Never heard of this? Length might make a difference, but coiling? Most likely corrosion or wear of the receptacle...is it snug?
     
  9. kpic

    kpic New Member

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    Is where you are plugged into a 110V 30 amp or a 110V 20 amp outlet?

    Are you using one of these adapters:
    http://www.homedepot.com/p/GE-30-Amp-to-20-Amp-Adapter-Plug-AD3020/202307108

    This is a 30 AMP outlet:
    http://www.homedepot.com/p/GE-30-Amp-Temporary-RV-Power-Outlet-U013P/202307113

    This is a 15 amp:
    http://www.homedepot.com/p/Leviton-Renu-Prairie-Sage-15-Amp-Outlet-Color-Change-Kit-018-RKR15-0PS/202761960

    AC needs 30 amps or the same kind of outlet a camper or clothes dryer plugs into. If you are plugged into a standard 110V house plug, the AC is drawing so many amps it will make the cord get hot.

    If you are plugged into a 30 amp, next is make sure the wires are the correct gage.

    I'm a Ham operator; however, a real electrician can explain it better than me. ;)

    Edit:
    As a Ham, I know how to do it, but explaining it is often more of a challenge than doing it correctly.
     
  10. jayco1997

    jayco1997 New Member

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    If the cord is coiled, it is added length to the cable that you might not actually need, so if you only needed the amount required you cut the cord therefore only using the amount needed without having extra. In this situation here the distance would be minimal because we are not talking about very long cable runs which would be carrying tons of current. The other thing that could affect the cord would be other cables running nearby but again, that probably isn't the situation in the pup.
     
  11. Camp-N-Nuts

    Camp-N-Nuts KrustyKamper

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    Note: I did use that caveat. [;)] I was talking about coiling not length here...
     
  12. rabird

    rabird Howdy!

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    Clean the prongs on the plug (fine sandpaper) and spread the prongs apart slightly for a tight fit. If loose wire in outlet, clean the wire and tighten.
     
  13. djohnsn

    djohnsn New Member

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    The cord seems to be an appropriate length (it is not coiled), but the plug is somewhat loose in the receptacle. I think that I will go ahead and replace the outlet, check for loose connections, clean the prongs on the plug, and verify the wiring size. Further testing will have to wait until this weekend.

    I was plugged into a 30 amp outlet at a Texas State Park.
     
  14. SUPERKSR

    SUPERKSR Member

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    I just remembered seeing the push-in, spring loaded connectors on the back of the 15 amp recepticals. Don't use these.
    I don't know why they even exist - except for the speed of installation.
    They simply aren't as safe as using the screw terminals with a clockwise loop on the end of the wire.

    I'm not sure if the 20 amp receptical for your A/C has the push-in type of connectors.
     
  15. Unstable_Tripod

    Unstable_Tripod Well, there's your problem!

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    If a cord is hot it radiates heat into the air. If it is coiled up much of its surface is in contact with other parts of the surface (the coils touch each other). Therefore it can't radiate as much heat and the entire coil gets hotter than the same length of cable would if it were stretched out (so 100% of the surface could radiate heat).
     
  16. steved

    steved New Member

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    I saw first hand a 100 foot cord wrapped on one of those (orange) handheld reels turn the inner coils black, melt the reel, and smoke after only using a short time with a 100 watt light bulb...NEVER coil a extension cord tightly around anything for more than a couple wraps. They make a sort of magnetic field (coil?) that causes the heat to be concentrated if I remember my physics correctly? Sort of like induction heating.

    If its concentrated at one point (I think the OP indicated right near to the receptacle), I would suspect the cord is faulty where it is hottest; like from partially broken strands in the wire itself.
     
  17. Camp-N-Nuts

    Camp-N-Nuts KrustyKamper

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    To quote OP, " It is only hot fairly near to the plug itself. Is this something that I should worry about? If so, any ideas about why it is getting hot?"
     
  18. steved

    steved New Member

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    If it is just a section of the cord getting hot, then I would suspect the cord is damaged internally (individual strands of the conductor have been broken causing it to act like a smaller gauge wire). If its the plug, then the plug might be bad (same reason above).

    If you have the length to play with, chop off the offending section and install a new plug. Short that, install a new cord (and maybe one long enough to dedicate to the AC from the stantion?)
     
  19. tombiasi

    tombiasi Well-Known Member

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    It has more to do with magnetic flux generated in the wire. Each wire will generate a small magnetic field but will be canceled out because the wire next to it has current flowing in the opposite direction. A coil is providing transformer action where each turn multiplies the field. Many turns and high current are needed in real life to have to worry about it.

    Tom
     
  20. steved

    steved New Member

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    Hate to tell you, I witnessed it first hand...with nothing more than standard house voltage and a 100 watt light bulb for draw. The cord was melted into the reel, and charred. I have no doubt it would have caught fire had we not noticed it smoking.
     

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