sundance-communications.com/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring Conduit

Does anyone know of an online guide for conduit sizing? I'm looking at the possibility of 50 CAT 5's inside a conduit. The customer wants all lines run in conduit. It is a retail space, and the showroom ceiling consists of steel trusses. I envision a main run down the center, with smaller conduits breaking off to serve groups of outlets. The only guide I have lists conduit up to one inch.

Thanks,
Vern

Totally depends on Length of conduit and number of bends. If it was just a 12" sleeve through a smoke wall 1.5" would be fine. For a 10' piece straight between floors, I'd run 2". If you have bends and are goiing to be adding cables in the future you should beusing 2.5" or 3". Gets pretty pricy as the size goes up.

I can get about 5 CAT5 in .5" pipe,
13 max in a .75" pipe and about 75 to 80 in a 2" pipe. That is a full pipe. You are only supposed to fill it 60% so the numbers I'm giving you are illegal.

Hope this helps.

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You are only supposed to fill it 60% so the numbers I'm giving you are illegal.

Umm, no. The NEC does not specify conduit fill for LV wiring so there is nothing "illegal" to worry about.

Notice that the chart TTT provides is made up from data supplied by BICSI and cable manufacturers, that is where you need to look for fill recommendations on these cables.

-Hal

Ouch, break out the lube. Since this is a long run, pull boxes would be required,not only for pulling, but to break out smaller conduits for serving individual outlets. My idea is to let the electrician run the conduit after getting some sort of plan together.

Man that is a perfect candidate for Cable tray of some sort. Run you main rte. and still run your little condiuts up to the tray. it would make life easy and would look really good. just a little food for thought i love it when cable tray is put in for infastructure cabling.

tray sounds good and then let them paint the ceiling after. I hate the new open air no ceiling state of the art looking offices.

Ouch. 5 Cat5's in a o.5" Get out the lube is right!

One tip. Try to never use half inch conduit on new installs. They fill up too fast especially if any rg is ever run in them. They are also very unforgiving when trying to run more cable in with existing (ie its hard to get more in with the bends and twists and weaving). We always spec minimum 3/4 to the EC.

If you are doing many drops conduit runs can get very expensive very fast because of the expansive need for pull boxes. Conduit is relatively cheap compared to the boxes and LB's, See what you can do to centralize the boxes even if it means adding a few more lengths.

Is it NEC code that the conduit has to have pull boxes every 100 ft or so? Seems like I remember this was mandated by nec.

Is it NEC code that the conduit has to have pull boxes every 100 ft or so?

No distance requirement, that's up to you. A pull box is required after 360 deg of bends. In other words you can't have any more than 360 deg worth of bends per run.

-Hal