I have been told to size the conduit for poke-thru devices based on the cross-sectional area. I'm planing on feeding an office furnatures with 24 cables (cat 5e) thru the opening, but as you all know, there is a seal tight flex (1 1/4"C) goes to the furnature. My questions, what is the max number of cables I can run thru this poke-thru device assuming the O.D. is(0.20). Should I use the cross sectional method to figure the number of cables, which in that case 36 cables? (The cables are running in an open space)
POKE-THRU DEVICES
- Thread starter sam34
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hbiss
EC, Westchester, New York NEC: 2014
- Location
- Hawthorne, New York NEC: 2014
- Occupation
- EC
Re: POKE-THRU DEVICES
I think you need to look at the manufacturers instructions to see what they recommend. This is similar to any other fire stopped penetration and much depends on what materials you are using.
-Hal
I think you need to look at the manufacturers instructions to see what they recommend. This is similar to any other fire stopped penetration and much depends on what materials you are using.
-Hal
Re: POKE-THRU DEVICES
Hal-, thanks for replying. Actually I was reading thru the manafacture instruction and they said we could size it based on the cross- sectional area which in my case I could run 36 cables thru it, but I thought this is a vialation for the NEC since that will exceed the 40% filling (about 80%). Per NEC I should run only 19 cables in 1 1/4"c.
Hal-, thanks for replying. Actually I was reading thru the manafacture instruction and they said we could size it based on the cross- sectional area which in my case I could run 36 cables thru it, but I thought this is a vialation for the NEC since that will exceed the 40% filling (about 80%). Per NEC I should run only 19 cables in 1 1/4"c.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Re: POKE-THRU DEVICES
Technically the 40% fill applies to conduit that is longer than 24". Conduit nipples 24" or less have a fill of 60%. Don't know if this helps you. Just a thought.
Technically the 40% fill applies to conduit that is longer than 24". Conduit nipples 24" or less have a fill of 60%. Don't know if this helps you. Just a thought.
- Location
- Windsor, CO NEC: 2017
- Occupation
- Hospital Master Electrician
Re: POKE-THRU DEVICES
ATROEMI, what are "poke-through devices"?
ATROEMI, what are "poke-through devices"?
luke warmwater
Senior Member
Re: POKE-THRU DEVICES
a poke through device is basically a round floor outlet box.
they usually are pretty long with a nipple that goes to a j-box attached at the bottom and usually go in a concrete floor that requires a core drilled hole.
a poke through device is basically a round floor outlet box.
they usually are pretty long with a nipple that goes to a j-box attached at the bottom and usually go in a concrete floor that requires a core drilled hole.
luke warmwater
Senior Member
- Location
- Windsor, CO NEC: 2017
- Occupation
- Hospital Master Electrician
Re: POKE-THRU DEVICES
Ok....
So now I've seen one...
Under what circumstances would I say, "Hmm, I need a poke through device here."
Ok....
So now I've seen one...
Under what circumstances would I say, "Hmm, I need a poke through device here."
southernboys
Senior Member
Re: POKE-THRU DEVICES
I see there rated for 15A wouldnt have been smarter to have them rated for 20A so that I can pull my usual #12 wire to em rather then having to buy a roll of #14 wire or am I missing something?
I see there rated for 15A wouldnt have been smarter to have them rated for 20A so that I can pull my usual #12 wire to em rather then having to buy a roll of #14 wire or am I missing something?
hbiss
EC, Westchester, New York NEC: 2014
- Location
- Hawthorne, New York NEC: 2014
- Occupation
- EC
Re: POKE-THRU DEVICES
Per NEC I should run only 19 cables in 1 1/4"c.
There is no NEC fill requirement for low voltage.
George- You would use these where you need floor boxes in a fire rated concrete floor.
Southernboys- No reason you couldn't pull #12s and put them on a 20A circuit, these just use 15A receptacles.
-Hal
[ April 19, 2005, 11:41 PM: Message edited by: hbiss ]
Per NEC I should run only 19 cables in 1 1/4"c.
There is no NEC fill requirement for low voltage.
George- You would use these where you need floor boxes in a fire rated concrete floor.
Southernboys- No reason you couldn't pull #12s and put them on a 20A circuit, these just use 15A receptacles.
-Hal
[ April 19, 2005, 11:41 PM: Message edited by: hbiss ]
- Location
- Massachusetts
Re: POKE-THRU DEVICES
Originally posted by georgestolz:
Under what circumstances would I say, "Hmm, I need a poke through device here."
- Location
- Windsor, CO NEC: 2017
- Occupation
- Hospital Master Electrician
Re: POKE-THRU DEVICES
Ooooohhhhh. Hey, I see the light bulb glowing now.
Ooooohhhhh. Hey, I see the light bulb glowing now.
Re: POKE-THRU DEVICES
Are all poke-through's fire rated? What if I want an outlet under the conference room table, and the floor doesn't need to be fire rated? Do I still have to pay for the i-in-intum-intumescent (stuttering) material?
I usually try to stick with the 40% fill. I have been told (I'm an engineer - they don't actually let me touch with the wires) that a conduit is pretty full at 40% (with a lot of the empty space being between the wires). And the preformance of Cat 5E is pretty sensitive to squished or deformed wires.
Are all poke-through's fire rated? What if I want an outlet under the conference room table, and the floor doesn't need to be fire rated? Do I still have to pay for the i-in-intum-intumescent (stuttering) material?
I usually try to stick with the 40% fill. I have been told (I'm an engineer - they don't actually let me touch with the wires) that a conduit is pretty full at 40% (with a lot of the empty space being between the wires). And the preformance of Cat 5E is pretty sensitive to squished or deformed wires.
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