Posted By: dwflood Duct capacity - 11/13/08 08:31 PM
I'm installing new voice/data to a building appx 200' away from existing building. A trenching contractor is going to do a directional bore and provide PVC duct.

I need to pull a 50-pair PIC and 6-strand outdoor-grade fiber through new PVC duct. What size duct should I ask for? I guess 3" should be good, no?
Posted By: skip555 Re: Duct capacity - 11/14/08 05:19 AM
2" would do the job and 3" will give you plenty of room for latter pulls
Posted By: KLD Re: Duct capacity - 11/14/08 06:17 AM
.......and put in an innerduct to pull in that fiber. It is to protect the fiber from crushing caused by the PIC. Pull in the PIC and innerduct at the same time...fiber to follow.

But to answer your question....3" for sure. Industry standard is 4".
Posted By: Silversam Re: Duct capacity - 11/14/08 05:44 PM
One of the things we used to do, was to pull innerduct in to the pipe first and fill it (3 @ 1" or 1.25" innerducts in a 4" conduit).

Later the duct was available for multiple pulls without worrying about damaging the other cable.

We also used that "sock" stuff (soft, multi section duct whose name I can never remember)

Posted By: bfdatacom Re: Duct capacity - 11/15/08 08:59 AM
I think the "sock" that Silversam is talking about is "Maxcell". Also, Berk-Tek and Optical Cable Corp. both make outdoor fiber that is tight buffer if you don't want to mess with terminating loose tube fiber.
Posted By: Silversam Re: Duct capacity - 11/15/08 03:15 PM
Maxcell it is. I could never remember the name.

Posted By: mdaniel Re: Duct capacity - 11/15/08 03:34 PM
Yep, we have also used Maxcell.
Good stuff.
Posted By: dwflood Re: Duct capacity - 11/15/08 04:29 PM
Thanks everyone! I like the idea of an interduct pull with the pic. Do you think 3" duct is ok for 50-pair pic and a 1.25" interduct? The duct is going to be about 275' in length, in more or less a straight line, with a 90 bend at each exit point.
Posted By: EV607797 Re: Duct capacity - 11/15/08 05:08 PM
Eh.....I'm not too crazy about 3" unless your 90's are long sweeps (utility-grade). Standard 90's are a bit tight for pulling innerduct. Other than that, 3" will be plenty.
Posted By: tiggrrrz Re: Duct capacity - 11/10/09 08:11 AM
Be careful about the number of bends on the duct as well but, a 3" should do it as long as the bends are sweeping or no more the 3 90 degrees.

100%....pull a flexi-pipe inside the 3" for the fibre for protection. If you do this, ask the customer for a 4" because the pipe will take up much more room than the fibre so, it will leave you will additional room to pull another cable if you need to for re-inforcement, repair, etc.
Posted By: jacktel Re: Duct capacity - 11/10/09 10:54 AM
Funny note:
I sold a reel of outdoor 5e plant cable to a customer of mine as he wanted to link 2 of his buildings which were built 10 years ago.At that time he buried a 1" pvc flexible water pipe 250ft. in length between them. He tried to pull 3 RG59 cables and the 5e,he kept snapping the RG59s and ended up pulling 1 RG59 and 1 cat5e.He had numerous holes dug in lawn{looked like foxholes}to find crushed section and patched with a plumbers rubber boot. I tested the 5e yesterday and total length was 416' which of course is over the 300' network length needed. I don't know how much of a savings water pipe is over regular conduit but he and a couple of guys wasted most of the weekend trying to wire or dig.
PS: The RG59 cable was from China and for indoor use only.John
Posted By: hbiss Re: Duct capacity - 11/10/09 11:08 AM
Actually our standard for burial from pole to building or building to building has always been 4" regardless of the number of pulls, assuming that they don't exceed the 4". In that case we install another 4".

It's only a few dollars more but you will kick yourself if the pull is hard or you have to add more later.

Posted By: KLD Re: Duct capacity - 11/10/09 05:13 PM
.....and what is funnier is that this is a tag on a one year old thread.....

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