CAT5 to carry 120v power!!

[scuba_dave]

OK, this is what another Christmas decorator wants to try
Everyone that has responded to the thread has said NO!!!!
Don't try it, don't do it
He has decided not to try it

I've been holding back on asking, but thought I'd give it a shot. When animating a display, extension cords and power distribution become an issue. If going 100% LED's with all channels drawing less than half an amp, is it possible to use CAT5 (4 pairs of 24 AWG wire - 8 conductors) network cable with a 16 AWG ground to supply eight channels with one cable. With four color mini trees, channel eating mega-trees, and channel eating leaping arches, there is a lot of extension cord that could be saved.

The idea is to use DB-9 connectors with eight pins dedicated to the 24 AWG wires from the CAT5 cable and then use a 16 AWG common ground. 24 AWG wire can easily handle a half amp, and 16 AWG can easily handle the 4 amps common ground. At about 12 cents a foot for CAT5 cable, and under 10 cents a foot for the 16 AWG ground wire you have 20 cents a foot in cable for 8 channels of control - or about 2.5 cents per foot per cannel. This woud like be getting a 100 foot extension cord for $2.50. Add a couple DB-9 connectors at $2 each and you are still on the cheap. I'm thinking of using some of the 6/9/12 foot 18 AWG extension cords at the end that the lights would plug in to. So, my custom cord would be a DB-9 connector that plugs in to the controller - CAT 5 cable - pig tail the 8 extension cords at the end of the CAT5 run.

I understand the CAT5 is not made for 120VAC, but if all conductors are run on the same phase with a common ground there should never be a voltage potential between the conductors. The ground will be seperate from the CAT5 cable. With such a low current draw, heat should not be an issue. There will be a voltage drop over long runs, but should not be an issue for LED lights.

[suemarkp]

Cat5 no - that is only allowed for communications circuits. If it was CL2 cable, it may be possible if you have a something that limits the total VA consumed (and I think that limit is per cable and not per pair). I think the limit is 30VA, so that will only allow 1/4 amp. There may even be a voltage limit to CL2, and 120V would push you into CL1 category. The CL2 cable would also have to be rated at 150V or more (I think just about everything is 300V now, but it must be so marked).

I think 120V to ground on a DB9 is a bad idea (will the shell be grounded?). Hopefully its all female pins if he tries this!

I think I'd look for an outdoor rated cord that is multiple conductors in the 16ga class. I'm sure it exists, but you won't find it at home depot. But even 18ga multiconductor direct bury outdoor cable (which you can get at home depot) would be a better choice than cat5. But again, you'd need to check the working voltage limit of the cable.

[scuba_dave]

A Telco worker responded that they push between 48 & 100v DC on CAT5 all the time. And that the newer T-1 lines will push 230v DC
That seems like a lot of power to me??
Is the transmission different for DC/Telco setup?
IE, not constant?

[suemarkp]

Telco = Communications, so they can do whatever they want with CM type cabling. Increasing the voltage doesn't mean there's a lot of power. Usually, the voltage is increase to reduce noise issues and to be less affected by voltage drop. They could be sending .01 amps at 240 volts.

Technically, you can do this if the cable has a high enough voltage rating and the connectors don't arc over (or fry you when you handle them). The NEC does not like to use things outside their listed domain. That can be frustrating for people who build things and know there is no difference between CM rated 24ga wire and CL1 rated 24ga wire. So there's a big difference in what will work (and even work safely) and what is NEC legal.

The important things for the original plan would be overcurrent protection for each of those wires, and I'd want a GFCI source circuit. I'd be comfortable with a half amp slo blo fuse on each 120V line. For any wire that is going to be draped outside repeatedly, the wires should be stranded instead of solid. So I'd want stranded cat5 which is harder to find, or find something else more suitable (like the direct bury 18ga 7 conductor cable I bought at Home Depot for my outside alarm sensors).

[scuba_dave]

Thanks for the clarification
They didn't say how many amps Telco pushed
He did say under 1a in a roundabout way