I have a job I am trying to get a run of wire through an existing underground 3/4" conduit. There are wires already in the conduit. I tried to get a fish tape through it but it is stopping underground somewhere. I tried to pull on one of the existing wires to use it as a "pull wire" but they don't budge. I tried to go to the other end and "hook" my other fish tape, and now that fish tape is stuck. I don't want to pull too hard in risk of damaging the existing wires in the conduit. I'll probably cut my fish tape and leave it in there:( I knew I was risking getting it stuck, but had no other alternative at the time. The house is probably 70 + years old and I don't know when the wiring was done. It is in a historical district, and in it's time, was a mansion. Still it's a very nice house with a very large yard.
The pipe terminates outside in a 6x6x4 junction box underground, flush with the grass. There is another empty 3/4" conduit leaving the j box, seemingly going in the same direction I want to go. I pushed a 100 ft. fish tape in it and could feel where it might be going through a 90, but cannot locate it anywhere. I've looked under the house, in the yard etc. Can anyone think of a idea I could use to locate this pipe? The original one goes under an asphalt driveway, and I'm assuming this one does too, since it is headed in that direction and is only about 6 ft. from the edge of the driveway, and I feel no resistance when pushing the fish tape, until I reach the end of the fish tape( 95 ft. in the ground). Digging is sort of out of the question, since there are scrubs lining the length of her house where the conduit may be headed. ( by the way, this is where the "troublesome" conduit is coming out too). If I could find this conduit, I possibly could use it for my homeruns back to the panel. I've thought about maybe getting a helper to see if he could here the fish tape, while I twisted it and moved it around. Anybody got any other suggestions maybe? This is to be a "high tech" job for a "high end" customer, and I've just started. I did caution the customer that there might be problems if I could not get the wire through the conduit, before she signed the contract, but I was hoping for it to go easy:(
I guess my "gut" feeling was right. Any suggestions would be greatly appreciated. I have to go back Monday or Tuesday to try again. Thanks for the input.. Steve...

Empty conduit? The helper is not a bad idea. I have also used my variable spd drill to spin/flip the snake before with a tywrap on the trigger.

Metal conduit? Use a tone generator with a 9V battery.

Sparkync,
You can rent locating equipment from some rental stores or hire a locater (probably a better idea) to come to the job site. Since you now have a fishtape in the conduit, connect the transmitter to the fishtape or place the inductive probe around the fishtape and you should be able to easily find the route of the conduit and mark the ground with upside down paint can. Compared to digging up the shrubbery and all that, locate services are very cheap, and also make you look like a professional looking out for the best interests of your client.

I watched a backhoe operator witch an empty pvc with two 3 foot stainless welding rods. I like a little more technology so I prefer an air compressor.

Whenever the topic of tracing conduits comes up, someone is sure to chime in with stories about 'witching.'

To test these theories, the folks at the Sceptical Enquirer actually arranged a test ... pipes and cables of various material, crossing a parking lot that was under construction. Each was marked at the start, and the lot backfilled and graded. Then, various "witchers" were asked to trace the runs.

Despite considerable effort, SE was not able to find any who could trace even one. Several of the :experts" asserted that the trial was, in some way, unfair. It seems the method only works at places other than test sites, and only when no one is watching.

Not that there is not any value in being able to 'read' the surroundings. Sometimes ground contours, building layouts, and other features can give you valuable clues as to where the pipes have been run.

I'm assuming that the 3/4 is rigid metallic. Sounds like a collapsed pipe maybe? This is pretty common here in southern cali, especially near the ocean where soil is extremely corrosive.

You could use an inexpensive in-ground tracer tied to one of the existing wires. I have one I picked up for about $180 and I've had very good luck with it, granted the conduit is not too deep. Otherwise, I agree with homer - get a locator service and avoid all the headaches and wasted labor hours.

Good Luck!

Generally backhoes and excavators are good at finding pipes usually when your not looking

I don't guess I explained it quiet well enough. The pipe I'm trying to find is an empty 3/4" pvc run. The other pipe that has the wires from the panel,is rigid when it goes into the ground from the house, but pvc when it comes into the 6x6x4 "j" box in the yard. It goes under an asphalt driveway from the house, and this is about where my fish tape stops. I figure the pipe is corroded into. The wires in the pipe won't even budge.
The pipe I'm trying to locate is empty and comes back out of the 6x6x4 j box in the yard, and heads back in the direction of the house or garage,(it seems). That is the reason I'm trying to find where it goes, to see if I can tap into it (if it comes out on the other side of the driveway) then go under the house where I can take it back to the panel or "j" box under the house. I found out I can rent something like a metal detector that will trace my fish tape when I push it through. It cost $75.00 a day.I may have to go this route. I have one other option that may work. There is already a circuit in the j box that goes to an automatic gate, and a switch leg that goes to a post lamp down at their little bridge over their creek. I can get my hot feed from there, and use the switch leg for the lights I am going to install. The lights will pull approximately 9 amps (possibly- (3) 250wt. HPS floods, (1) 150 wt. HPS flood, and (1)100wt. HPS.) My only concern is when the gate shuts or possibly opens when the lights are on, it might create an overload and trip the breaker.
Hope this explains it better. Thanks... Steve

Steve:

Would it be possible to try compressed air on the empty conduit? I know that it's a stretch, but the air may either make enough mess or create enough noise to where you can find the other end.

I encountered a similar situation to yours several years ago, but it was about a 300' run of 1-1/2" RMC, about 50 years old. It had a telephone cable in it that we needed to pull out and replace, but it wouldn't budge. No fish tapes, no blowers, no nothing would work so we figured it was a collapsed/rusted-out conduit. We knew that the old cable had to be replaced, hook or crook, so at this point I was more interested in seeing the snake make it through than saving the existing cable.

Due to the property, also similar to what you've described, excavation really wasn't an option. I went for broke and hired Roto-Rooter to come out and give it a try. He was able to run a snake through with a slow spin on it. He obviously knew what he was doing. It turned out to be lots of rust and dirt that the snake managed to loosen enough to not only get the snake completely through, but to dislodge the old cable so we could pull it out. Oh, and by the way, he ran the snake without any kind of cutter head on it; just the raw end of the snake.

I know that in your case, this might not be an option, but I thought I'd throw out another possible solution just in case you run out of ideas.

Steve:

Would it be possible to try compressed air on the empty conduit? I know that it's a stretch, but the air may either make enough mess or create enough noise to where you can find the other end.

I encountered a similar situation to yours several years ago, but it was about a 300' run of 1-1/2" RMC, about 50 years old. It had a telephone cable in it that we needed to pull out and replace, but it wouldn't budge. No fish tapes, no blowers, no nothing would work so we figured it was a collapsed/rusted-out conduit. We knew that the old cable had to be replaced, hook or crook, so at this point I was more interested in seeing the snake make it through than saving the existing cable.

Due to the property, also similar to what you've described, excavation really wasn't an option. I went for broke and hired Roto-Rooter to come out and give it a try. He was able to run a snake through with a slow spin on it. He obviously knew what he was doing. It turned out to be lots of rust and dirt that the snake managed to loosen enough to not only get the snake completely through, but to dislodge the old cable so we could pull it out. Oh, and by the way, he ran the snake without any kind of cutter head on it; just the raw end of the snake.

I know that in your case, this might not be an option, but I thought I'd throw out another possible solution just in case you run out of ideas.

I've used the following trick successfully to trace an in-ground, empty conduit:

Since the pipe (or part of it) is metal, you cannot attach the toner unit of the tracer to your fish tape, as the tape will make ground with the pipe and negate the tracer readings, so what you do is tape a scrap roll of insulated wire to the end of the fish tape and feed both into the pipe. Once you hit the end of the run (either the break or the next box), you cut the wire and attach the toner to it, then the other side of the toner to a large screwdriver and stick it in the ground. Now trace the wire in the pipe.

It's important to make sure the wire is insulated from the fish, so it's a good idea to wrap the cut end with a little rubber tape before you attach it to the fish, just to be sure.

Follow the trace until you loose it, and that should be pretty close to the end of the run. If the readings at the end of the run seem funny, you can just paint your line as far as you can, then use the length of the wire and/or fish that come out of the pipe to give yourself a pretty accurate distance.

If you don't own an in-ground tracer, you probably want to think about picking one up if you're going to be doing this kind of work. I didn't think I needed to own one until I bought one, and it's probably one of the best investments I've made. It paid for itself after 1 or 2 jobs, and it's made and saved me quite a bit of money since.

Good luck!

Found it!!!! I went to the last resort and rented a locator. The owner said she didn't want to use the "gate circuit" so I had no option. I started out thinking the conduit was pvc, so I rented the locator thinking I could trace my fish tape through it. After a very confusing morning with the locator, I find out that it is rigid coming out of the 6x6x4 j box, so I just had to touch the conduit with the fish tape with the prob hooked to the fish tape. It led me to the old pipe that was already there. Thinking It may have led me wrong, but hoping for the best, I started digging down to find the old conduit on the other side of the driveway, then to my great surprise, there were both conduits side by side about 18" deep. Well, the conduits were about 8 ft. from the front wall of the house, and went under a bunch of hedges. We started digging again at the wall of the house, and went as far as we could go without taking up her 6ft. hedge:( One last try, I went back to the other side of the hedge at the driveway, and tunneled under the hedge as far as I could go, and Wow!!!!I seen the conduit we were looking for making a 90 up, so I new I had found it. Started pulling the dirt and mulch away, and found another 6x6x4 j box buried under the mulch with both conduits terminated in it and the existing wire that was going out to the other j box in the grass. I stuck my fish tape back in and pulled the circuits I needed out to the j box in the grass. What a relief. I was about to have to "scratch" this project, if I couldn't find it. This was my last option. I think I will make a rough layout of the j box and leave it at her electrical panel in her basement, just in case someone else runs into the same problem down the line. I will have to cover the j box back up under the hedges, I guess, for "looks", but I may stick something there to mark it someway:) Thanks for the input. I guess it was the remark about renting the locator that sent me in the right direction. It pays to share our ideas here. Thanks a bunch for all the input. Steve.....

Thanks for sharing the outcome, Steve. It's impressive that you chose to be so persistent where many others would have thrown their hands up and walked away. While we appreciate the magnitude of your efforts, I sure hope that your customer did too. Far too often, they don't have a clue and since they don't have a point of reference, they have nothing to compare your efforts to.

Ed, it was a combination of things that made me persistant.
#1. I don't like to start a job that I can't finish
#2. I didn't want to let the customer down
#3. I NEED THE MONEY
Steve....

I smell what you're cookin'. I guess we all feel that way in various forms.

Most gate openers I've seen run on 12 volt batteries with a trickle charger.

They run on the battery but the power supply is usually big enough to run them without the battery. When my wife took over her community all of the batteries were dead and unplugged.