View Full Version : Finding Fiber in PVC?
Trying to locate a 2" PVC with a multi-mode loose-tube 12 strand fiber in it that is buried about 12"-18" below grade and about 1100' long.
What would be the most efficient way to locate the pull boxes without using trial and error with a shovel?:-?
Thanks for your help.:smile:
JohnME
10-30-2007, 10:13 PM
WOW- I am going through the same problem right now. The problem for me is that the boxes are buried in a baseball field somewhere, no one knows where.
I was told that theres a device that will clamp onto a metal fish tape, after you push the fish tape into the conduit then the mate to the device will then locate the conduits.
I will be using this device later this week, I will provide a name of it at that point, I have not seen it yet in person.
480sparky
10-30-2007, 10:21 PM
WOW- I am going through the same problem right now. The problem for me is that the boxes are buried in a baseball field somewhere, no one knows where.
I was told that theres a device that will clamp onto a metal fish tape, after you push the fish tape into the conduit then the mate to the device will then locate the conduits.
I will be using this device later this week, I will provide a name of it at that point, I have not seen it yet in person.
They're called locators.
Rycom (http://www.rycominstruments.com/1-Utility-Locating-Home.asp)
I hope it works. I'm sort of in a jam with this situation. The existing fiber is around 20 years old with a bad fusion splice. I was thinking of using it as a pull string but I am pretty sure that there are some wild bends in the conduit run and am reluctant to go for it. The closest box I could locate is 300 cable feet away!
Denis
10-30-2007, 10:31 PM
send an unexperienced ditch witcher out and let him work his magic :roll:
quogueelectric
10-30-2007, 10:44 PM
The person who ran the conduit used conductive tape to mark out the run so you can easily clip a transmitter on it and tone it out. stick a steel snake in as far as you can from both directions and tone and mark out the run with the little stakes that can be cut by a lawnmowwer like little flourescent wiskers
Engineer83
10-31-2007, 08:00 AM
Another trick would be to use a fiberglass rodder. Take a spool of #12 and electrical tape it to the rodder. This works pretty effectively. The one point I must stress is to make damn sure you tape it at 10 foot or less intervals. Otherwise, you will be in for a surprise when the wire and rodder doesn't come out. (personal experience haha) Then hook up the locator to the wire.
Also, it would be worth a chance to see if the fiber has an armored jacket. You might be able to scrap some of the jacket off CAREFULLY! Then clamp on the locator to the armor. Then make sure you tape up the armor well when you are finished.
ptonsparky
10-31-2007, 09:00 AM
The person who ran the conduit used conductive tape to mark out the run ...
Hee! Hee! That's a good one.
LawnGuyLandSparky
10-31-2007, 09:59 AM
Trying to locate a 2" PVC with a multi-mode loose-tube 12 strand fiber in it that is buried about 12"-18" below grade and about 1100' long.
What would be the most efficient way to locate the pull boxes without using trial and error with a shovel?:-?
Thanks for your help.:smile:
Are you sure there are any pull boxes?
dereckbc
10-31-2007, 10:05 AM
Check to see what the strength member is on the fiber cable or if it has a shield. If it is metal, clip the locator on it. Otherwise smart cable pullers run a single 14 or 16 gauge wire or a pull string with the cable for just such emergencies.
Are you sure there are any pull boxes?
I think there are more pull boxes because there are a couple of turns in the run from what maintenance has described. It would be an interesting pull if what I have found is/are the only boxes in the run.
LawnGuyLandSparky
11-02-2007, 11:44 PM
I ask because you said the closest box you could locate was 300' away. When FOC is pulled either through PVC or buried innerducts, 300' is nothing. I've seen MH's spaced 3000' apart.
If there is indeed a bad fusion splice, there must be a splice case, and the MH you're looking for should be more substantial than a handhole. And keep in mind, you could lose 300' easily in a slack coil, so a cable might be 1000' from splice to splice as the crow flies, but the bad splice is seen 1200 feet away.
Rampage_Rick
11-03-2007, 12:09 AM
I think there are more pull boxes because there are a couple of turns in the run from what maintenance has described. It would be an interesting pull if what I have found is/are the only boxes in the run.
300-foot S-curve pull through 2" PVC, consisting of a pre-loaded innerduct, 2x 25-pair OSP voice cables, and 3x CAT5E OSP. Kellems grips on everything, plus a buttload of tape and lube. Picked up the biggest swivels available at the tackle shop, and tugged with 1" mule tape. Used a Kawasaki Mule in 4WD-Low to pull it :D
Do you have any idea how hard it is to pull a pair of fiber cables through 300' of 1/2" innerduct? I'm glad I did it beforehand in the parking lot with the innerduct in a straight line.
I too have used the fish-tape and locator method. Might be difficult with pull boxes in between. I'd try the good standby: Shop vac, Jet line, wadded shopping bag. You might be able to get twine with a metallic tracer, but barring that you can always use the jet line to pull in some cheap wire. With a good-enough locator you quickly become adept at finding depth as well. (45° side-scan)
I ask because you said the closest box you could locate was 300' away. When FOC is pulled either through PVC or buried innerducts, 300' is nothing. I've seen MH's spaced 3000' apart.
If there is indeed a bad fusion splice, there must be a splice case, and the MH you're looking for should be more substantial than a handhole. And keep in mind, you could lose 300' easily in a slack coil, so a cable might be 1000' from splice to splice as the crow flies, but the bad splice is seen 1200 feet away.
I know exactly where that fusion splice is and I have made a visual inspection. It is in a buried box (16"x16"x8") and full of water. It is one of the boxes I found that is about 300' from the next box in the run.
don_resqcapt19
11-04-2007, 06:38 PM
It is in a buried box (16"x16"x8") and full of water.
Sounds like a small enclosure for a fiber splice point.
Don
Rampage_Rick
11-04-2007, 09:23 PM
Yeah I wouldn't dare try to cram a Tyco FOSC in a box that small. Plus in the event of Moves/Adds/Changes it's helpful to have enough slack to reach into your van/truck/pup-tent.
quogueelectric
11-04-2007, 10:55 PM
They havent used them since dinosaurs roamed the earth. Ditchwitch 950 on ebay @200$ PRICELESS
cowboyjwc
11-05-2007, 07:13 PM
Try blowing air in the pipe. I've found broken water lines this way.
electricalperson
11-17-2007, 01:36 PM
ideal makes a pretty decent tracer http://www.professionalequipment.com/xq/ASP/ProductID.4009/id.5/qx/default.htm
i used it before to locate wires underground and it works pretty well..
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