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H3RRS

SPT 1 OR SPT 2?

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Hello All,

I will be making all of my own extension cords for my first show in 2018. I notice there are two different kinds of SPT wire. For those that use this merhod, which kind do you use? What's the main difference?

As always, it's truly appreciated! 

- H3RRS 

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I always use SPT1. SPT2 is a little thicker coating if I remember correctly.

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SPT 2 is usually 16ga (~10A) , SPT 1 is 18ga (~3A)

Do but the correct wire for the Vampire plugs you buy. SPT 2 will not fit SPT 1 vampires  (I just returned a roll that I got from a high shelf and only looked at the shelf tag)

SPT 1 in a SPT2 vampir might miss the prong or worse, the same lead hits BOTH because it is possible to be crooked.

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Thanks all! You're all truly so kind, helpful, and patient with me as I have many questions in preparation for my first show next year! 

Again, thank you! 

Edited by H3RRS

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So just a little info on the SPT wire.

From the Christmas designer.com web site:

Understanding the Difference Between SPT-1 and SPT-2 Cord
By Jason Woodward | Published: November 7, 2011

We frequently get questions regarding the difference between SPT-1 and SPT-2 wire. There is a lot of confusion and even long time professional Christmas installers don’t fully understand the difference and what makes one better than the other.

When installing Christmas lights and decorations, zip cord and light line are often used. These are usually made from 18/2 wire. However from time to time 16/2 cord may also be used and in some cases a very thick 14/2. But since most Christmas lighting and decorating projects utilize 18/2, we’ll focus on that for now. When looking at the two numbers for the zip cord, 18/2, the 18 refers to the size of the wire, which in this case is 18 gauge. The 2 means there are two wires that make up the cord. The smaller the number, the thicker the wire. So a 16 gauge cord is thicker than a 18 gauge.

As far as the SPT rating, this is simply the thickness of the insulation that surrounds the copper wires. 18/2, SPT-1 wire has an insulation thickness of .030″ and 18/2, SPT-2 has insulation that is .045″ thick.

Because of the thicker insulation, SPT-2 wire has a higher maximum amp rating than SPT-1, which means it can power more lights and decorations. 18/2, SPT-1 is rated at 7 amps and 18/2, SPT-2 is rated at 10 amps.

Because SPT-2 is thicker it is often recommended for cold conditions where the insulation tends to get brittle and cracks. However, in our own testing as well as feedback from other pro installers, we’ve found that the thicker insulation actually tends to crack easier when it gets cold whereas the slightly thinner SPT-1 tends to be more pliable which reduces cracking due to cold temperatures. Like many issues within the Christmas lighting field, this is a topic of much debate and everyone seems to have their own opinion regarding which option is better. However, SPT-1 is still the most often used type of cord and we sell it about 10 to 1 over SPT-2.

For most installations, our recommendation is to go with SPT-1 unless you are looking to run longer lengths of incandescent C7 or C9 lighting. If you’re using LEDs, then the 10 amp rating on the SPT-2 cord is not necessary. The reason why is due to the lower electrical requirements of LED bulbs. With a 10 amp rating you could run over 1100 bulbs on a single run. However the issue is that the amount of footage of perimeter cord it would take to hold this many bulbs would be so long that you would get extreme voltage drop and all the bulbs would not be properly illuminated. Typically we don’t recommend running more than 400 feet of 18/2 cord. Otherwise you will start to get voltage drop. By going with18/2, SPT-1, you’re saving money upfront and the 7 amp rating is more than enough for most applications, especially when using LED Christmas lights.

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44 minutes ago, Santas Helper said:

So just a little info on the SPT wire.

From the Christmas designer.com web site:

Understanding the Difference Between SPT-1 and SPT-2 Cord
By Jason Woodward | Published: November 7, 2011

We frequently get questions regarding the difference between SPT-1 and SPT-2 wire. There is a lot of confusion and even long time professional Christmas installers don’t fully understand the difference and what makes one better than the other.

When installing Christmas lights and decorations, zip cord and light line are often used. These are usually made from 18/2 wire. However from time to time 16/2 cord may also be used and in some cases a very thick 14/2. But since most Christmas lighting and decorating projects utilize 18/2, we’ll focus on that for now. When looking at the two numbers for the zip cord, 18/2, the 18 refers to the size of the wire, which in this case is 18 gauge. The 2 means there are two wires that make up the cord. The smaller the number, the thicker the wire. So a 16 gauge cord is thicker than a 18 gauge.

As far as the SPT rating, this is simply the thickness of the insulation that surrounds the copper wires. 18/2, SPT-1 wire has an insulation thickness of .030″ and 18/2, SPT-2 has insulation that is .045″ thick.

Because of the thicker insulation, SPT-2 wire has a higher maximum amp rating than SPT-1, which means it can power more lights and decorations. 18/2, SPT-1 is rated at 7 amps and 18/2, SPT-2 is rated at 10 amps.

Because SPT-2 is thicker it is often recommended for cold conditions where the insulation tends to get brittle and cracks. However, in our own testing as well as feedback from other pro installers, we’ve found that the thicker insulation actually tends to crack easier when it gets cold whereas the slightly thinner SPT-1 tends to be more pliable which reduces cracking due to cold temperatures. Like many issues within the Christmas lighting field, this is a topic of much debate and everyone seems to have their own opinion regarding which option is better. However, SPT-1 is still the most often used type of cord and we sell it about 10 to 1 over SPT-2.

For most installations, our recommendation is to go with SPT-1 unless you are looking to run longer lengths of incandescent C7 or C9 lighting. If you’re using LEDs, then the 10 amp rating on the SPT-2 cord is not necessary. The reason why is due to the lower electrical requirements of LED bulbs. With a 10 amp rating you could run over 1100 bulbs on a single run. However the issue is that the amount of footage of perimeter cord it would take to hold this many bulbs would be so long that you would get extreme voltage drop and all the bulbs would not be properly illuminated. Typically we don’t recommend running more than 400 feet of 18/2 cord. Otherwise you will start to get voltage drop. By going with18/2, SPT-1, you’re saving money upfront and the 7 amp rating is more than enough for most applications, especially when using LED Christmas lights.

Thank you Santa's Helper!

This information was very helpful. You said you use SPT 1. Do you have any issues sending power to your lights? 

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1 hour ago, H3RRS said:

Thank you Santa's Helper!

This information was very helpful. You said you use SPT 1. Do you have any issues sending power to your lights? 

Just Standard Hardware issues: Too Long or Too Short :D

 

IMHO get som Flag Zip ties and  a fine point Sharpi. Labee both ends, even if it is just a unique number.  saves 'follow that cord'  #54 where are you (plugged in)

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1 hour ago, TheDucks said:

... #54 where are you...

Looks like somebody else around here used to watch officers Toody and Muldoon.

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I made some cords out of SPT-2. When doing so I learned to be careful to just push the wire in and not pull along the wire when it's touching the teeth. Of the first eight I made, two did not work when I hooked them up.

when I took them apart I had a tooth laying flat under the wire instead of having bit in. 

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What ever you start with, stick with it, I started with SPT-2  when I ran InCans.  I stick with is so I don't have to worry about what plugs go with what cord.  Just easier to stick with one and save headaches later.   

 

Just my two cents

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