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Extension cords standard Gauge to use?


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Hi Everyone,

 

I've been looking at acquiring more extension cords, being my first year I thought i would ask what gauge is recommended? That way I can spend the money once.

 

what do you guys recommend?

 

Thank you,

 

Chad

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A lot of people, including me, make our own cords using spt 1 (18 gauge) and vampire plugs and receptacles. For anything over 9' long, it's a more cost-effective option than sale-priced store-bought. Unless you'll be pulling an extreme amount of power that should do just fine.

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George is right. I prefer SPT2 which has more insulation. Its a little more expensive though. Another BIG consideration is space. The typical extension cords from HI centers take up a lot more space. About 3-4 times as much space.

 

Try action lighting or just Google "SPT1, SPT2 extension cord"

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Before hearing from you guys I thought premade cords were the route to go, mostly because of ease. But now I feel being able to add outlets mid way through the cord will be very beneficial an actually make connecting certain areas a lot easier.

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Great link, very helpful. Thank you

no problem.

Like Ken said for your longer runs it's easier just to make them to custom length. Last year I bought 1000 feet of SPT-1 cord thinking that's plenty for my small display, wrong! I had to make a mad dash to HD to buy another 500/600 feet of extension cords.

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Im on it thanks... what is the major difference of the SPT1 and 2?.. is it the guage? i would have max 32 channels.

http://www.christmas-leds.com/category_v3.aspx?categoryID=372

Quick copy & paste from the Christmas-leds website

What’s the difference between SPT-1 wire and SPT-2? When making and installing Christmas lights or making your own extension cords, SPT wire is often used. These are usually made from 18/2 wire. When identifying the two numbers for the wire – 18/2 – the 18 refers to the size of the wire which in this case is 18 gauge. The 2 indicates that the wire is made with two wires.The SPT-2 wire has a thicker insulation. Because of the thicker insulation with the SPT-2 wire the user can power more lights and decorations than the SPT-1 wire SPT-1 is rated a 7 amps or 770 watts and has an insulation thickness of .030″.SPT-2 is rated at 10 amps or 1100 watts and has insulation that is .045″ thick.Use this information to help you evaluate your power needs. Do not exceed the recommended amperage, this will absolutely cause the wire to fail and be a hazard.If you are using LED’s to make your customized light strings, we recommend that you do not run more than 400’ of the 18/2 wire. The reason for this is that your chances of getting some voltage drop is likely and your bulbs will not illuminate to the best of their ability.If you are using Incandescent bulbs we recommend that you do use the SPT-2 wire.In a Nut Shell – The difference between SPT wire is the thickness of the insulation over the wires, not the amperage of the wire. The wire gauge or AWG rating is how much current the cable can carry in amperes.

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http://www.christmas-leds.com/category_v3.aspx?categoryID=372

Quick copy & paste from the Christmas-leds website

What’s the difference between SPT-1 wire and SPT-2? When making and installing Christmas lights or making your own extension cords, SPT wire is often used. These are usually made from 18/2 wire. When identifying the two numbers for the wire – 18/2 – the 18 refers to the size of the wire which in this case is 18 gauge. The 2 indicates that the wire is made with two wires.The SPT-2 wire has a thicker insulation. Because of the thicker insulation with the SPT-2 wire the user can power more lights and decorations than the SPT-1 wire SPT-1 is rated a 7 amps or 770 watts and has an insulation thickness of .030″.SPT-2 is rated at 10 amps or 1100 watts and has insulation that is .045″ thick.Use this information to help you evaluate your power needs. Do not exceed the recommended amperage, this will absolutely cause the wire to fail and be a hazard.If you are using LED’s to make your customized light strings, we recommend that you do not run more than 400’ of the 18/2 wire. The reason for this is that your chances of getting some voltage drop is likely and your bulbs will not illuminate to the best of their ability.If you are using Incandescent bulbs we recommend that you do use the SPT-2 wire.In a Nut Shell – The difference between SPT wire is the thickness of the insulation over the wires, not the amperage of the wire. The wire gauge or AWG rating is how much current the cable can carry in amperes.

That clears it up.. thanks for the info.

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  • 2 weeks later...

That clears it up.. thanks for the info.

yeah.. but it is technically inaccurate. 

The insulation is not the deciding factor in current carrying capability, it is the gauge of the wire. 

 

Here is an interesting table    http://www.houwire.com/pdf/article400_5.pdf  

Note the A and B designations.   Also note that SPT-1 and SPT-2 are rated the same for current allowance

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yeah.. but it is technically inaccurate. 

The insulation is not the deciding factor in current carrying capability, it is the gauge of the wire

correct and very important!

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yeah.. but it is technically inaccurate. 

The insulation is not the deciding factor in current carrying capability, it is the gauge of the wire. 

 

Here is an interesting table    http://www.houwire.com/pdf/article400_5.pdf  

Note the A and B designations.   Also note that SPT-1 and SPT-2 are rated the same for current allowance

the link is causing a 404 error

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Ok, so this is an "older" thread but I can't help myself. I do agree with the stp cord, and wish I had done it myself originally. If you think about it, it makes a lot of sense. A lot of what we do draws very little power per element. It might be one or two flood lights, two candy canes with a total of 50 mini lights. It makes no sense to use an outdoor cord for that kind of draw. I would spend some money on the main feeds to the controllers if you need extension cords there, or of course things like house outline c7/c9 incandescent. Those are your largest power draws.

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I wish I had known about this a few years ago, BEFORE I bought 1 1/4 miles of extension cords.  :angry:

Could have been worse...could have been 5.7 miles :D

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Technically I would agree with you. And in our application this is true. But when you start stuffing wires into conduit then the insulation does make a difference. Thats why my friends they make a table showing wire with SJO, THHN,  THHT and so forth. Now wouldn't be just a wee bit easier to make a table with just the wire gauge and one entry for current? Its just there is no real difference in SPT-1 and SPT-2.

 

So, I have to say, yes the insulation does make a difference as to how much current a given gauge of wire will carry. But in our hobby we dont have to split those hairs. And did you know that again the current rating will change depending on how populated the conduit is stuffed....... Just food for thought. Suppose we can call it desert and not the main course for us..

yeah.. but it is technically inaccurate. 
The insulation is not the deciding factor in current carrying capability, it is the gauge of the wire. 

 

Here is an interesting table    http://www.houwire.com/pdf/article400_5.pdf  

Note the A and B designations.   Also note that SPT-1 and SPT-2 are rated the same for current allowance

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Technically I would agree with you. And in our application this is true. But when you start stuffing wires into conduit then the insulation does make a difference. Thats why my friends they make a table showing wire with SJO, THHN,  THHT and so forth. Now wouldn't be just a wee bit easier to make a table with just the wire gauge and one entry for current? Its just there is no real difference in SPT-1 and SPT-2.

 

So, I have to say, yes the insulation does make a difference as to how much current a given gauge of wire will carry. But in our hobby we dont have to split those hairs. And did you know that again the current rating will change depending on how populated the conduit is stuffed....... Just food for thought. Suppose we can call it desert and not the main course for us..

Hi Max,

 

Actually in the context of "extension cords" the insulation of these two wire types plays no role.  It does however for standard wiring in a raceway as you pointed out.. It is good food for thought for those that run conduits out to their lawns and fill them with wire. 

 

Like you say though.. in our hobby.....  B)

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