atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Outside Plant OSP Construction Cable locating advice

Was hoping some of you outside plant guys could help with a problem. The tower side of our biz is currently in the process of replacing the building Lightening Protection system of a 13 story condo that was damaged by huricane Ivan. To make a long story short, they have been through numerous General Contrators and the place is a mess. What was left of the roof was demo'd and replaced with one of the rubber membrane type roofs. Problem is they have covered over the 6 downleads that go to ground with the rubber membranes. I have the fortunate task of going around with the roof man and letting him cut holes in the roof trying to find the original downleads. Now for the question, is there any type tool I could use to help me locate the downleads withought tearing up the enitre roof? We have one of those undergound type tracers we bought at an auction, but I tired it out on the ground ring of the tower here at our shop, and of course the fact that the cable is grounded is killing the Tone. I'm not well versed in the use of the tracer, and after months of trying to find a manual for the thing, I found it was'nt much help either. The only thing I can think of, is I am able to actually find where the downleads are tied to ground, dissconnect it from ground, then should be able to attach the "Toner" there. Any tips from you outside wire types would be greatly appreciated, I do not relish the thought of having them tear the roof to pieces. Man, this is how Ev must feels while posting.......might get used to this. Just trying to give as much info as possible. Thanks.

You guessed it...disconnect the lead where it goes to ground and place one lead to conductor and the other to the ground and go hunting for tone.

I was hoping I would'nt have to find the rods, I neglected to mention the building was built in 62, and is of poured concrete construction. As of yet, we have been unable to find the orgianl grounds, we do have a copy of the original plans, and the best we can tell is they were put in the concrete columns. The building has been remodled so much since 62 the plans bare only a slight resemblance to what we can acutally see and get access too. May have no other choice but to tear up the roof. If we can't find the originals, after making a few holes, we'll suggest running new downleads down the sides of the building.

If you can disconnect the cables thats the way to go. You may check if someone has copies of blueprints and locate them that way.

Telcomtex is correct. You want to isolate the end you are toning from, from grd. That is probably the biggest mistake most people make when locating cable. The other end your tracing too will have to go to ground to follow the line. Hope that all makes sense.

whoa, you guys are too quick for me. You have to get to one end of the cable or the other. If you can't find either end you're screwed. The only way to locate through induction is on power.

Here's an old farmer trick that Ditchwitch actually made into a cable locator with a swivel handle. We take two #10 bare wires, bend 4-5" down, leave 10-12" out horizontally, and very loosely hold the wires (sweaty hands help). When you walk over the best ground (like water) the wires will cross.

It's called "witching". And it works. And, no, I am not crazy, just ask Mitch.

:thumb:

KLD

"you're screwed" Story of my life.

That's what I figured, I was hoping that if by chance we did find one up top, I could hook the Tracer up to that one, and locate the rest. Was hoping for that magic bullet, but looks like I'm gonna have to use it to put myself out of my misery. Thanks for the information, guys.

Have you tried a good metal detector. A good one should be able to tell the difference from the roof and ground wire.

But, Reb, once you get one, a Dynatel locator with multiple freqs used in the inductive mode should let you have ALL grounds up there. Have you found a red iron attachment for the cathodic ground? Try it to the locator then to a ground rod. Sometimes it will act as a transmitter to other grounded cables. Or the MGN ground on the main power ground entrance to the locator to the ground rod. I'm thinking (boy, will that get me in trouble!) that you should get "flood" signals on all grounded cables. To get an exact reading you'll need to get between the ground and the ungrounded cable but this should give a "shadow" reading for a guestimate of the location.

Good luck.

KLD