Communication Cabling between floors

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ISSLDR

Member
I have a client that has requested we pull telephone cables 10 floors. I suggested we make a service loop for support but the building IT manager advised to run the cable in their existing 8" conduit and no support for the 110 lft drop would be necessary. I can not find the requirements for support when running this vertical distance. Can someone point me in the right direction. Thanks, Whiskeredone
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
If you are really uneasy about no supports you can always attach the cables to a support rope or something and drop that down the tube.
 

ISSLDR

Member
I had considered a steel aerial cable due to the 10 cables but could not find a reference. Everything seems to lead back to Art.300. I guess the best thing is to get the AHJ approval. Thanks for the guidance.
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
I had considered a steel aerial cable due to the 10 cables but could not find a reference. Everything seems to lead back to Art.300. I guess the best thing is to get the AHJ approval. Thanks for the guidance.

Steel cable you might need to ground. I would stick to a non metallic method if possible in that case.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
Since you didn't get back to me with specifics I can tell you that there is nothing the Code or AHJ is going to say about the execution of the work. About all it addresses is the spread of fire and smoke IE: fire stopping and proper type cable for the application. If you let the end go and it goes down the rabbit hole and winds up in a big pile on the first floor they couldn't care less. Again, I don't know whether there will be multiple pairs to each floor, one straight run bottom to top or the pair count required. One thing I do know is that if it is a straight run some kind of support or strain relief will be required as a design issue.

The other thing I know is that an IT person is NOT who you should be looking to for advice.

-Hal
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Nothing to do with it. It's simply how do you support it so it doesn't go back down the hole. And HOPEFULLY he's not using CAT5.

-Hal
If the cable is long enough and supported only at the top it will stretch under its own weight. For that reason you need to know the allowed working tension (which may be lower than the pulling tension) and the weight per foot.
Agreed, this may not be a limiting factor with comm cable and only 100 vertical feet.
 

ISSLDR

Member
Whiskers

Whiskers

Thanks for the tip on NEC 300.19. The IT guy wanted (and got) 10 C5 and 3 CAT6 cables) ran while we were on another job. The IT guy was my project coordinator until I showed him the code reference. That got him away from the owner. We went back and ended up making service loops on every floor to relieve tension. I later spoke with AHJ and he seems okay with it. Inspector is checking me this week. I'll check Bicsci tonight but hope the inspector is happy. I will let you know what he says.
 
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