Using existing conduit for outdoor lighting

Hi all. My driveway is about 450-feet long and very dark mid-way down. As fate would have it, there is a telephone pole mid-way down the driveway where electric and telephone go underground and ultimately lead to my house.

I had natural gas installed and while doing so, the telco had to locate and mark the fiber path. They couldn't because, well, it's fiber. So they used a snake to pull a kind of rope through that I guess allows them to find the conduit. That's when I got the bright idea that maybe I could pull electric cable through there. It's a 2" conduit with nothing but a tiny piece of fiber in it. Would code allow me to share this conduit with the fiber? I'd want a 20A circuit for a post lamp and receptacle. I guess I'd mount a junction box on or near the pole (I don't own it but it's on my property).

 

Do you own the conduit? How is it terminated on each end? What is the burial depth?

 

Good questions. I *assume* I own the conduit because there's no utility right-of-way on the survey. It's definitely on my property. It's about 24" down and open on both ends where it comes out of the ground.

EDIT: I just re-read my original post. The power cable from the utility does not share this conduit. Just the fiber from the telco.

 

It's a bit of a grey area, but if you consider this a "duct" instead of a conduit it would be allowed to pull a separate wiring method through it. In other words you could not pull individual conductors like you would in a normal conduit, but you could pull a cable (UF-B) or another smaller electrical conduit through it.

I do have some practical concerns. First is that a 500 foot single shot pull is going to be tough and will require a lot of force and create a lot of friction in the pipe. This could easily ruin the fiber cable. I'm sure the telco chose to use the 2" conduit to be gentle on the fiber and not introduce any twists, sharp bends or high tension in the pull. If you were to do the pull, the safest thing to do would be to pull the fiber out, then pull the fiber and the electrical cable back in as one unit. The second concern is how to enter and exit the duct. While the 24" depth is ok, any wiring method would need to be protected on entrance and exit. If you had some sort of enclosure or gutter over the duct where it enters and exits the ground you could probably make it work. The third concern is voltage drop. Nearly 500' is a long way to run residential voltage. You would need #6-2/g UF-B cable to get a 15A circuit that distance. That much cable is of course rather expensive and heavy, leading to a higher pull tension and back to my first concern.

If you don't mind taking the risk of ruining the fiber and potentially having to eat that cost, I'd say give it a shot. Otherwise, have you looked at solar powered lights and a battery box?

 

Where is this 500 foot pull? Maybe I'm reading it wrong but it sounds like he wants to go from the house to the pole that is half way down his 450 foot driveway. That sounds to me like a 225 foot conduit/duct, not 500 feet.

I'm still leery of using that conduit/duct but at 250 feet (more or less) the circuit IS do-able.

 

If the fibre and conduit serve your house no right-of-way or easement is required. My money says the conduit is telco property and they won't allow you to use it.

 

Yes I'm looking to go about 200-225 feet through whatever this thing is (duct or conduit). The marking company used a snake to fish the marker tape through it.

Hadn't really thought about solar and batteries. Definitely an option. I don't need a ton of light down there.

 

So I had a better idea. I'm going to have the power company install a meter on a pedestal (that I will install) right by the aforementioned pole. That way I don't have to use the conduit in question nor trench from my house to the pole. I'm going to run some lights and receptacles off of a breaker panel on that pedestal. I won't be able to control them from inside the house, but I don't really care. I'm going to put photoelectric sensors on them anyway. And if I really want to shut them off I can do it at the pedestal (or if I install switches at the lights - not sure what code is).

So now the question becomes what to use for underground cable. I can't go very deep (probably no more than a foot) because of natural gas piping that runs the length of the driveway and pretty much where I need to run wire. I would also have to cross over buried water and sewer lines, electrical and telephone wires. So, again, I can't go too deep. Suggestions?

 

If you can't go more than 1' deep, you'll have to use threaded rigid metal conduit. You would use either THWN or XHHW wires in the conduit.