Fire sealing for floor penetration, low voltage wires?

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brycenesbitt

Senior Member
Location
United States
If I ran some wires between floors I would normally fill the hole with itumescent caulk and be done with it.

Here I've been asked to install a large conduit for telecom wires, which is to receive additional wires in the future.
It goes straight up from an unfinished electrical service room, to a carpeted occupied room above (a classroom actually).

How should this be fire sealed, yet allow future additional pulls? And can you provide any code citations?
Jurisdiction is California USA. As a low voltage job, it no permit has been pulled.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
If I ran some wires between floors I would normally fill the hole with itumescent caulk and be done with it.

Here I've been asked to install a large conduit for telecom wires, which is to receive additional wires in the future.
It goes straight up from an unfinished electrical service room, to a carpeted occupied room above (a classroom actually).

How should this be fire sealed, yet allow future additional pulls? And can you provide any code citations?
Jurisdiction is California USA. As a low voltage job, it no permit has been pulled.

Is the conduit just a stub from floor to floor? I can't recall where I've seen it, but I believe LV wire has to be protected where it passes up through the floor for (I think) about 6" above the floor. So you should have a pipe sticking up slightly above the carpet in the classroom. If you have just a few cables in, say, a 4" pipe, you might put those in a separate 1" conduit inside the 4" and fire seal everything. When they come back, they'll pull the fire seal out of the 4", leave the seal alone in the 1", and maybe stick another 1" in the 4" for the new cable. Seal it all up again. Rinse and repeat until you run out of room. Otherwise, if you run the cables naked in the large conduit, you have to scrape everything out each time you add another cable and repack the entire penetration.
 
Just put a large junction box at top of the conduit with a bushed box connector... pop out or drill an opening for the wires you run and install a bushing there... fire stop around wires in that bushing and screw on the box cover. When you run more wires you have the option to clean out that bushing or add another
 
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If I ran some wires between floors I would normally fill the hole with itumescent caulk and be done with it.

Here I've been asked to install a large conduit for telecom wires, which is to receive additional wires in the future.
It goes straight up from an unfinished electrical service room, to a carpeted occupied room above (a classroom actually).

How should this be fire sealed, yet allow future additional pulls? And can you provide any code citations?
Jurisdiction is California USA. As a low voltage job, it no permit has been pulled.

http://www.roxtec.com/us/market-segments/telecom/wireline/
 
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