atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring Water in the pipe

We went to residential customer to tie in his guest house to his main house with a 12-pair and two cat 5e's (not OSP) in underground pipe.

When we take tape off of one end of the pipe in the basement, a good amount of water pours out, and when we stick the fishtape into the pipe on the other end we hear nothing but water slushing around.

So I tell the G.C. that I'm not running cable in a pipe full of water and tell him to let us know when it's all flushed out.

The next time we hear from the customer he says that the contractor said that there is ALWAYS water in underground pipes. Is this true, is there always water in pipes and we just run cable anyways? Should we just run OSP cable and be done with it? Any advice is welcomed...

Yes, you should be running OSP through underground conduit.

There will always be some moisture, condensation caused by temperature differences at the two ends of the conduits. But the standing water should be sucked or blown out, and if it fills up again, the source should be found and corrected.

I'll leave it to others to admonish you to install protection on both ends, but I know that us Californians aren't going to do it in your particular situation.

The water is always going to be there, the contractor is correct. Use cable suitable for direct burial. By the way there is no such thing as OSP CAT5. No telco would ever use it for Outside Plant.

-Hal

Sorry, Hal, you can get OSP Cat5 from several sources. I used it about 10 years ago in a conduit between school buildings. Ain't pretty but it worked. And, yes, it was icy pick and black sheath. Stiff as can be. Could have pushed it 100' without a pull rope.

As far as the water...yep, water will naturally fill the pipe. It is better to clear it prior to installing your cable but it will return. Condensation.

I got mine from a company that is now named Rexel.

Good luck.

I have quite a bit of it too, made by General Cable. It's not quite as rigid, but the overall design isn't quite as good as regular OSP cable. There's no way to ensure a completely dry pipe in the ground, that's for sure.

So bottom line is he should flush it out (which I think he did by now) but we've gotta face the fact that water always gets into underground pipes. I'll tell my boss that we gotta run outdoor cable. We've got 12-pair and cat5e OSP cable, complete with icky-pick.

Touch Tone, how do you know that I won't install protectors on both ends? Maybe I will, actually you're right, I won't...

Thanks fellas.

True, the pipe will be dry for a few days, but that will change the next time it rains. I've never understood how a pipe can fill with water when it rains, yet it seems to be water-tight enough to never empty.

Yes, you should do this job under OSP specs, as if the cables are buried directly in the ground. Personally, I think that underground conduit actually invites water. Direct-burial cable seems to be much more trouble-free.

Unless you are willing and capable of performing splices in approved splice closures, it is a safe assumption that you aren't providing proper protected terminals. Protected entrance terminals just aren't made for fewer than 25 pairs. I am not sure that they ever were made. A proper building entrance terminal requires a 26 gauge fusible link, so those dinky little punch-down blocks with protectors cannot ever be compliant. This fusible link must be 24" long, so you'll either need to use a stubbed 25 pair BET and splice just the 12 pairs to it or use something like THIS

You can do it right or do it wrong and money is insanely tight these days. That is entirely up to you and for obvious reasons. Advice is all that we can offer here, but it is obvious that tight budgets result in corner-cutting in invisible areas. Proper protection isn't needed until after it was needed if you know what I mean.

Off the subject just a hair for the osp side of things. I encountered numerous problems in a 5 story mortgage company where they had conduit running underneath the concrete on the floors. Apparently when the building was underconstruction there was a severe rain storm which evidently allowed a lot of water to seep into these sub floor conduits. I found them while recertifying some data cable we had recently worked on while doing a MAC project. Using an Agilent wirescope 350 they were all failing return loss, without any exceptions. When we finally got permission to repull cable in the conduits from the customer we found that over the years the plenum sheath had been completely impregnated with water and so had the the pair sheathing causing this problem. We ended up pulling and replacing all of the cable running in these conduits inside two identical buildings, after drying the conduit's thoroughly (jetline and a lot of rags in a continuous loop, shop vaccing the overflow as we went).

NEC considers ANY conduit run underground or cement pad to be a WET location

I'm sure it was all beautifully clear spring like water too!