sundance-communications.com/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring underground telephone cabling between 2 buildings

The plant cable can come 50 feet into a building, but you still have to transition to air core cable to punch it down.

Exactly, Bill. Many filling compounds in cable are flammable. Most manufacturers have abandoned petroleum-based waterproofing compounds, but since we never know where cable is manufactured anymore, we have to assume that the filling truly is 'grease'. A filled cable punched down in an exposed environment is the equivalent of a leaking oil line.

Zane, please don't think that I'm belittling you or any other viewers of this thread. I think that you've raised a valid question that warrants a detailed answer. In the United States, the National Electrical code mandates most installation standards with regard to wiring standards of just about any type. On that note, we also have to keep in mind that most enforcement of NEC standards is performed by the local authorities. In most cases, these agencies' resources are limited, so they can't afford to hire inspectors who really know what they are doing. It is up to us as contractors to do what is right. Just like the plenum vs: non-plenum cabling requirements. Most inspectors in these parts focus more upon things like firewall penetrations, etc. I know for a fact that most don't even look to see if the correct cable has been used.

Back on topic: Who in the heck would want to punch down a filled cable on a block? Wipe the icky-pick from the pairs all that you want, but it will keep coming back. That is the purpose of it's design. It will ooze out of the cable core for decades. Every time that you so much as punch down a jumper, you'll be wiping your fingers on your pants.

Cable designed to be directly-buried should be just that: Buried directly. It doesn't belong indoors under any circumstances, it isn't necessary in underground conduits or in the air unless the installer just doesn't understand the difference between outside plant and inside wiring standards.

OSP cable is limited to 50 feet within a building for a good reason: The jacket is made from Polyethylene. So is the insulation on the individual pairs. This material is high-density and therefore allows 'thinner' tolerances, resulting in 'thinner' cables. When pulling massive cables in ducts, reduced sizes make a huge difference.

Those of us in the interconnect business consider a few hundred pairs to be a big deal. There is a huge difference when a telco is trying to squeeze a 2,700 pair cable into a 90-year old duct between manholes. These are two truly different and unique industries, comparable to the IT/interconnect impasse.

One of the independent telcos (GTE) in my area often allowed filled cable to be installed in an aerial environment. While they don't do it now since they became Verizon, they still have plenty of buried filled cables directly entering aerial splice closures. When it is hot outside, you should see the goo dripping out of them. It is nasty.

It is really quite simple. Just terminate the OSP filled cable using a listed BET that has a legal splice compartment where the flammability issue has been addressed.

Zane, I'm sorry that you made the mistake of asking me for the time and I told you how to build a watch, but I just felt that you had asked a legitimate question that warranted a detailed answer.

Ed,

I never complain when someone teaches me something new. I don't have much background in outdoor plant. I have to tell you that I have seen more direct buried cables punched down to 66 block (most lightning) than I have transistioned. Telco is always that way, but now that I know what to look for, I bet there is a lot of it.

You can install any type of cable and it won't matter...until the Inspector RED TAGS your work.

Do it right the first time.