Fiber Optic Question

[Bruce Hooke]

Hey Gang,

I've got a quick question that I hope someone here can answer. I am helping lay some conduits between two buildings and one of the things that may end up one of the conduits is a fiber optic cable to provide a network connection between the two buildings (which are about 600' apart). The fiber optic cable would get its own conduit. The key question is, if we get the fiber optic cable already made up with the ends polished and the end fittings attached, how big are those end fittings? The key issue, of course, is how big the conduit needs to be to allow the pre-made-up cable to be pulled through it.

Thanks!

- Bruce

[cs]

The one and only time we ran fiber they ran the cable and than did the termination. So I guess I don't know the answer.

Chad

[JTA]

2nd what Chad said. That is how it is done here. However, to answer your question you need to find out what type of connector you will be using. ST, SC...

Jack

[mmd]

I used to build CATV & fiber-optic systems way back when fiber was in its' infancy. I'd run the cable without fittings, leave a generous coil (20 feet or so) at either end, seal the ends o fthe cable well with shrink-wrap, and let the technician installing the later equipment do the end polishing and figure out what connection devices he wants to install. As for conduit size, always assume that what you have will be too small in five years, so while you have the ditch open, put in the biggest that you can. For a communications conduit I wouldn't put in smaller than 1-1/2" diameter unless I really had to. I'd also put a strong nylon or polypylene line through the conduit, tied off to something permanent at each end, to pull the next cable through with. Always leave a chase line in the conduit!

[Donn]

The size of the terminal fittings depends on the size of the FO cable, and you definately run it through the conduit before termination.

[cs]

What Michael says, oversize conduit. Bellsouth makes us run a 3" (yes I said 3") conduit for their phone lines (into the builiding).

Chad

[Bruce Hooke]

Thanks everyone. It sounds like the answer is to pull first and then get a tech on site to do the terminations. Is the reason to do it this way simply that the end terminals do not apperciate being dragged through a conduit?

- Bruce

[Donn]

Right. The terminal fittings are mechanically connected, and can easily be loosened or jarred out of contact during the pull. Depending on the difference in diameter between conduit and cable, and the type of jacketing on the cable, it isn't always an easy pull.

[JimM]

Be careful. Fiber can't be run through 90 degree elbows, use sweeps. As of buying fiber with the ends made up? Yes. Talk to the supplyer of the fiber and see what size conduit to use. Fiber can't be kinked and needs special care when you are pulling it.