MPP/CMP Cable & Conduit

[lwilmot]

I should know the answer but I have gone "brain dead". The university requires that all conductors and cables be run in conduit. We are installing some new data circuits and the contractor was asking how many 4 pair, 24AWG MPP/CMP cables could be installed a 3/4" conduit. I just can't think my way through this and would appreciate some direction.
Thanks,
Le

 

[bphgravity]

Conduit fill restrictions do not apply to communication cables in raceways. See 800.110 and the exception.

 

[don_resqcapt19]

While the code rules do not cover this, most manufactures have wire fill limits for their cable. In many cases their wire fill numbers are less than what you would get if you did a 40% fill based on the area of the cable. Remember that these cables do not have the strength that power conductors do and excessive fill leads to pulling tensions that can damage the cable.
Don

 

[bphgravity]

Very good point, Don. I always neglect to mention that on this topic.

 

[ron]

If it is metallic raceway and applies to Article 800, wouldn't 800.110 direct you to

800.110 Raceways for Communications Wires and Cables.
Where communications wires and cables are installed in a raceway, the raceway shall be either of a type permitted in Chapter 3 and installed in accordance with Chapter 3 ....

The varied raceway specific section for Number of Conductors which directs you to the 40% fill table?
I can't find a similar reference in Article 830.

 

[don_resqcapt19]

Ron,
I think that you sto\pped reading too soon.

800.110 Raceways for Communications Wires and Cables
Where communications wires and cables are installed in a raceway, the raceway shall be either of a type permitted in Chapter 3 and installed in accordance with Chapter 3 or a listed nonmetallic raceway complying with 800.182, and installed in accordance with 362.24 through 362.56, where the requirements applicable to electrical nonmetallic tubing apply.
Exception: Conduit fill restrictions shall not apply.

Don

 

[hbiss]

You didn't read far enough. "Exception: conduit fill requirements will not apply".

-Hal

 

[hbiss]

An there you have it from us both...

The place to look for fill requirements is the cable manufacturers literature.

-Hal

 

[ron]

Thanks. Good Point!