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#10 AWG THHN Wire for offroad lights?

Discussion in 'Lighting' started by StaticFilter, Sep 4, 2011.

  1. Sep 4, 2011 at 3:09 PM
    #1
    StaticFilter

    StaticFilter [OP] Well-Known Member

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    I'm a commercial electrician and have access to a lot of leftover THHN #10 and #12 wire. Would this be an okay option for wiring 100W offroad lights?
     
  2. Sep 5, 2011 at 11:15 AM
    #2
    StaticFilter

    StaticFilter [OP] Well-Known Member

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    I know #10 wire is plenty big, the only thing I'm not clear on is if 10 gauge THHN will be okay for a DC system, as we use it in AC systems
     
  3. Sep 5, 2011 at 11:25 AM
    #3
    cummins6speed

    cummins6speed Well-Known Member

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    It will work the same on DC as it does on AC. It won't be as flexible as most automotive wire that usually has more, finer strands
     
  4. Sep 5, 2011 at 11:36 AM
    #4
    StaticFilter

    StaticFilter [OP] Well-Known Member

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    That's where my concerns lie, the stranding of the wire. As you said DC wire usually has finer stranding, is it because of how direct current works/flows or just for flexibility?
     
  5. Sep 5, 2011 at 11:51 AM
    #5
    UndefinedTaco

    UndefinedTaco I'll eat all your food.

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    Better then single solid strand wire..pain in ass to work with..looks like shit when routed half the time.



    Post up pics of lights when done and what you did. I can get ahold of #10G THHN too if needed..and if it works well..why pay for wiring..get it fo freeeeeee.

    I wonder if 12 AWG would work for 65 watt lights?
    I'd think they would...they don't pull THAT many amps..as I have a set unloaded on a 15A circuit right now..
    but it has 10G wire going through it right now
     
  6. Sep 5, 2011 at 12:22 PM
    #6
    SOSHeloPilot

    SOSHeloPilot Well-Known Member

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    FWIW ... when I use the normal stranded wire on vehicles ... I always "tin aka solder" the ends of the wires that will be connected.

    (keeps the ends of the wires from unraveling & shorting out later)

    .
     
  7. Sep 5, 2011 at 1:26 PM
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    StaticFilter

    StaticFilter [OP] Well-Known Member

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    When I had my previous Taco with 6 separate 100 watt lights up front, i was running 400w (4 lights) off a 30amp fuse, and another 200w (2 lights) as my fog light circuit. I'm not sure what i want to do this time around, i just figure if i run #10 to everything, it will be more than i need. I like 100w lights hehe
    gonna wire up bed/cargo lights and reverse lights also and maybe 4 offroads up front plus 2 fogs. I'd like to put a lightbar on the roof but that's $$$$
     
  8. Sep 5, 2011 at 3:09 PM
    #8
    cummins6speed

    cummins6speed Well-Known Member

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    65W/12V=5.42A per light so 12GA would be fine for up to 4 lights
     
  9. Sep 5, 2011 at 3:12 PM
    #9
    cummins6speed

    cummins6speed Well-Known Member

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    Wire is wire is wire. As long as it is sized for your load and the insulation is rated for the environment it is in you are good to go
     
  10. Sep 5, 2011 at 7:01 PM
    #10
    StaticFilter

    StaticFilter [OP] Well-Known Member

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    Hmm according to this chart (http://www.powerstream.com/Wire_Size.htm) 10AWG is good for 55A? That seems high, I thought it was rated for 40A... So I could run 6x 100W lights off 1 10 AWG circuit with a 55A fuse?

    **EDIT**Yeah I figured this didn't sound right. 10 AWG can handle 40A but is only rated for 30A
     
  11. Sep 5, 2011 at 7:02 PM
    #11
    StaticFilter

    StaticFilter [OP] Well-Known Member

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    Well, I know for example that welding leads are extremely fine numerous copper strands... has to be a reason

    **EDIT**
    Stranded vs. Solid Wire

    This one is a bit of a mind-boggler, but it's important. When electricity flows through a wire, it mostly flows on the surface of the wire, not through the middle. This effect is more pronounced on high frequency AC than it is on DC or low frequency AC. This means that a "wire" of a given size that made up of many smaller strands can carry more power than a solid wire - simply because the stranded wire has more surface area. This is one reason why battery cables in your car and welding cables are made up of many very fine strands of smaller wire - it allows them to safely carry more power with less of that power being dissipated as heat. However, this "skin" effect is not as pronounced in a typical 12V DC automotive application, and the wire and cable used there is stranded for flexibility reasons.
    When looking at a chart or description of wire capacity, take note of whether it is referring to stranded or solid wire - some charts may not specify but instead assume a default based on the typical wiring used in a given application. For example, almost all automotive wiring is stranded while almost all home wiring is solid. For most applications, flexibility or the lack thereof will be more important, but for very high frequency AC applications, stranded wire might be a requirement.
     
  12. Sep 5, 2011 at 7:03 PM
    #12
    PLC721

    PLC721 Well-Known Member

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    My Hellas were shortly wired with #12
     
  13. Sep 5, 2011 at 7:14 PM
    #13
    StaticFilter

    StaticFilter [OP] Well-Known Member

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