What guage wire?

Discussion in 'General Electronics Chat' started by spinnaker, Dec 13, 2014.

  1. spinnaker

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    I need to wire up some heating elements


    The info I have is the heating element is 10.9 ohms. They each consume a max 16W at 12V. If I did my math right that is around 1.3 amps max for each heater.

    They recommend 20 gauge wire in the instructions. If I am reading the wire charts right a 20G wire can handle 1.5 amps. Am I covered enough with 20 G wire or should I go up a gauge? Things seem to be a little tight so the smaller the wire I can get away with the better.
     
    Last edited: Dec 13, 2014
  2. cmartinez

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    What material would you be using for the wire? Nichrome 60?
     
  3. spinnaker

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    Not sure what I have on hand here. Appears to be copper. Standard Radio Shack hook up wire, stranded.
     
  4. cmartinez

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    Cooper is usually not good for use as a heating element... maybe if you did the math with this nichrome 60 table (the most common type of heating element wire) things would be more consistent. Each wire gauge has its own ohms/foot resistivity value.
    You can buy nichrome wire in that site, or Amazon, or Smallparts (now called AmazonSupply).

    EDIT: Maybe Radio Shack also sells nichrome wire... you'd have to check with your local store
     
  5. spinnaker

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    I am only going to need 4-5 feet (1.5 meters) .
     
  6. cmartinez

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    Bummer.... What's the specific use for that wire? What are you planning on heating up?
     
  7. GopherT

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    20 gauge wire is usually fine for a short run to a 10 ohm heater.
    Look up wire gauge on Wikipedia. They will give you the resistance per 1000 feet. You will see you will have a very low voltage drop across your copper wire if it is only a few 10s of inches. All voltage will be dropped across the 'resistor'.
     
  8. spinnaker

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    So in your opinion, 20 AWG copper would be OK for this application?
     
  9. spinnaker

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    Why is Nichchrom a better choice to wire for heating elements?
     
  10. wayneh

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    I see no reason to ignore that recommendation since you're only using a few feet. On the other hand, you mentioned tight quarters. If the small amount of heat generated in your #20 wire (which you can calculate) can't get away, it starts to become a concern. Are things so tight that #18 is not practical?
     
  11. GopherT

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    Nichrome is used to make the heating element. It is known as resistance wire. There was some confusion with your goal and supplies.

    Use copper to connect the power up to your heater. Use the heater you have. Don't look into the nichrome if you already have something.
     
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  12. cmartinez

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    Because it has a higher resistance/foot than cooper, and also it is highly resistant to corrosion at high temperatures...
    You may also consider using a string of very low value resistors (say 0.5 ohms) connected in series, and then glue them with silicone to whatever surface you want to heat up... just make sure that they're all able (together) to handle the 16 watts you want...
     
  13. wayneh

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    I think there was confusion about whether you were looking for wire to BE a heating element, versus to SUPPLY your heating element.

    Wow, those other guys type fast.
     
  14. cmartinez

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    I'm typing with both hands here, wayneh... ;)
     
  15. spinnaker

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    Yeah it is supplying a heating element. I am not trying to create one.
     
  16. MikeML

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    And it only took 15 posts to get to this point...:p
     
  17. Austin Clark

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    20 AWG is a little close to spec, especially if it won't have much room, any way to dissipate heat, or is close to the heating element itself.

    Is it a serious fire hazard? Probably not, especially if it's not ran often. However, err on the side of caution if you can, and get wire a tad thicker.
     
  18. MaxHeadRoom

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    I have made Ni-chrome foam cutters and usually use 14g, it is easily available, also the termination point needs to be some kind of heat sink connection, IOW a large surface area at the junction point.
    In extreme circumstances you would use appliance connecting wire that has a heat resistant insulation.
    Max.
     
  19. ian field

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    Oct 27, 2012
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    I sort of got the impression the OP has a heating element (rather than winding their own) - and wants to know what gauge wire to connect it up with.
     
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  20. cmartinez

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    I'm beginning to think the same thing...
     
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