LED C9 retrofits, how many are safe

[zvacman]

I am building custom C9 strings for outlining my roof line. I am running three channels one white, red, and green. I have C9 retrofit bulbs with 5 LED's in each bulb. I am estimating that it will take 115 bulbs per string at 12" spacing with SPT1 wire. Will it be safe to do them on 1 string each or would it be wise to try and break them up into 2 or 3 strings each? My roof is very steep 12/12 and I get snow early so mid season repairs are out of the question. Advice from experience of even professional training would be appreciated.

 

Z

[Mega Arch]

I am building custom C9 strings for outlining my roof line. I am running three channels one white, red, and green. I have C9 retrofit bulbs with 5 LED's in each bulb. I am estimating that it will take 115 bulbs per string at 12" spacing with SPT1 wire. Will it be safe to do them on 1 string each or would it be wise to try and break them up into 2 or 3 strings each? My roof is very steep 12/12 and I get snow early so mid season repairs are out of the question. Advice from experience of even professional training would be appreciated.

Z

At 115, you're fine with one strand. However, making your own stringers takes the fused protection out of your string. Just in case a lamp shorts out, don't want to rely on the LOR fuse. It's 15 amp and the SPT1 is 1/2 that. So in theory, you could melt your wire or burn it before the LOR fuse blows. Which will take out 1/2 your controller's lights until you replace it.

All this to say, SPT1 is fine for stringers and extension cords. But when using for stringers, I use fused vampires for safety.

http://www.actionlighting.com/spt-1-spt-2-fused-male-vampire-zip-cord-plugs-green-pack-12-plugs-100sptplugf/

Edited October 4, 2015 by Mega Arch

[Mega Arch]

I know there's a pride factor in making your own custom cords, but at 12" spacing, I think I'd buy the cheapest incandescent sets I could find and chunk the lamps. I bought some after Christmas to make my strobe stringers with for $1.99 each. Or since I'd be buying fused vampires, I'd probably order three of these at the same time. Then just make the 15 ft ones to plug into them. $32 for 100ft is just a little more than SPT1 and sockets.

http://www.actionlighting.com/c9-12-spacing-25-50-or-100-long-ready-made-strings-100slc912/

Edited October 4, 2015 by Mega Arch