Why Not Spt-1?

[bigguy 0]

Refresh my memory. What is the reason for using spt-2 over spt-1 ... besides the thickness of the insulation?

[cacoulter 1]

spt-1 is rated at 7 AMPs.

spt-2 is rated at 10 AMPs.

[CraigH 10]

But SPT-1 would be fine for LED, right?

[Clyde Lindsey 0]

I only have at max 4 or 5 strings of Walmart 100 count lights (example... 1 amp) on a channel at a time! SPT-1 is FINE for this. If I were to put 10 stings of LED's on, no problem. I use SPT-1 for my 5 channel arches. They have 1 box of Walmart lights (20' cords) and that's it! Perfect since they only cost me like $1.25 for 30 of them.

[cacoulter 1]

spt-1 would be fine for 15 strings of 100 count mini incandescents (5.7 Amp total) or 140 string of 70 count M5 LEDs (5.76 Amp total).

spt-2 would let you do 20 strings of 100 count mini incandescents (7.6 Amp total) or 200 string of 70 count M5 LEDs (8 Amps total).

Always do your math so you don't overload your circuit or your wires.

[JeffL 0]

SPT-2 builds bigger arms when you wind it up, similar to 16/3 extension cords. SPT-1 is all I use. I have used it for 4 years and it still looks as good today as when it was new. Granted I don't run over a few amps max on any one channel so I don't need anything more. If you need the extra couple of amps jump to SPT-2.

[Justin Smith 0]

spt-1 is rated at 7 AMPs.

spt-2 is rated at 10 AMPs.

I thought they were both rated for 8. I'll check the nec.

[JeffL 0]

From what I read, they have the same gauge wire, but because SPT2 has thicker insulation, the amp rating is higher on spt2. Always a good idea to double check the specs before making a purchase.

[Justin Smith 0]

I just checked, spt1, spt2, spt3 are all rated at 10A with 2ccc. 80% of that is 8.

[vkjohnson 7]

Remember that the length of your cord will increase resistance and lower the amp rating as well. All I am using is spt-1, but some of my channels will need 7.5 amps at over 100 ft. That will require higher gauge than most spt cord.

[Justin Smith 0]

Also be sure to buy water-rated wire. (SPT-1W)

[Entropy 0]

I thought they were both rated for 8. I'll check the nec.

SPT is the insulation thickness. You can get SPT-1 and SPT-2 in different wire gauges and hence different amp capacities.

[Justin Smith 0]

SPT is the insulation thickness. You can get SPT-1 and SPT-2 in different wire gauges and hence different amp capacities.

But the NEC table 400.5B says 18AWG SPT-1 and SPT-2 are both good for 10A maximum.

[Entropy 0]

But the NEC table 400.5B says 18AWG SPT-1 and SPT-2 are both good for 10A maximum.

??

http://www.northwire.com/PDF/SPT.pdf

[Justin Smith 0]

??

http://www.northwire.com/PDF/SPT.pdf

That also says #18 spt-1 wire is good for 10A.

[Luke Kamp 1]

I use SPT-1 because it is cheaper, and the maximum power input to a LOR channel is ~8 amps, so you shouldn't be putting that much through it anyway. I at most have 5 amps to one channel....you don't really need SPT-2 unless you're doing long runs or static stuff. And you shouldn't be using it for main controller lines unless you're running LEDs. Some people prefer the "protection" factor, I prefer the price....and my setup doesn't really call for it.

[Clyde Lindsey 0]

And you shouldn't be using it for main controller lines unless you're running LEDs.

Some people prefer the "protection" factor, I prefer the price....and my setup doesn't really call for it.

I have some low power controllers (only using LED) and I never once though about using SPT2 for the main line. It is possible, I guess, but for displays that change year to year I wouldn't advise it at all.

All though I must say I agree... price factor, as a college student, is a big consideration.

[Justin Smith 0]

You shouldn't be defeating the ground on your LOR. It's there for a reason.

[Entropy 0]

That also says #18 spt-1 wire is good for 10A.

I was making the point that SPT comes in varous gauges and ampacities but the point is moot in that the LOR controller has a capacity of 8A on each channel. I'd only sweat the wire gauge if I was doing a very long run to a high load but even then, some voltage drop isn't going to make much of a difference on incandescent lights.

[KStatefan 10]

NEC Table SPT-1 (30 mils insulation thickness) and SPT-2(45 mils insulation thickness)

20 AWG 2 Amps

18 AWG 10 Amps

16 AWG 13 Amps

[danj 5]

I posted earlier tonight on a different topic about whether or not I needed 18/3 wire or 18/2 wire. I found a post that says lighting does not need the grounding plug terminal. So can ya'll please verify that I am good with 18/2 SPT1 or SPT2? Let's not get 1/2 debate started again...

THANKS IN ADVANCE!!!!!

[vkjohnson 7]

Common practice is using spt wire. All of your lights have no grounding terminal anyway. Just keep track of your amp loads so you don't overload it.

[danj 5]

Thanks VK. I guess NEC must be interested in higher ampacity loads or something.... I appreciate the input!! Wanted to make sure when I spend some $$ on bulk wiring that I get the right stuff the first time.

[danj 5]

Here's what I have found in looking at HD & Lowes and digging around on internet quite a bit. HD has 250' rolls of SPT2 green 18/2 wire for $42 each. Lowes also has 18/2 250' rolls for $42, but it is SPT1 and is either black or white, can't remember which right offhand. I don't think I really care about black/brown/green, as long it is not white. Other than "not getting" 1000' rolls that you can get from some companies on internet, this is the best price I have found so far. The closest I have found is about $180 (plus about $20 or so shipping). Any feedback on this? I am thinking not a super big deal to do some splicing, so ok if I have some "oddball" lengths when using, say, four 250' spools. Thanks for any lessons learned ya'll can give me. This is my next step; I am almost finished fabricating the four mini trees I am planning to use this season.

Edited September 7, 2012 by deej012160

[Mcas4380 49]

DeeJ

Do you have a Menards in your area, they sell the 18/2 Lamb Cord 250' rolls $34.00 Full price. that would make $136.00 for 1000' and if they are local no shipping. now they do often have it marked down in the stores or on sale. I picked mine up last year for around $29.00 a roll.

http://www.menards.com/main/electrical/electrical-cords/extension-cords/18-2-250-black-lamp-cord/p-1462755-c-6410.htm