Cat 5 in Pipe

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Dean83169

Dean83169

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I was curious as to the method of figuring out how many cat 5 wires to fit inside a piece of EMT. Does the standard pipe fill follow the same rule or not since its under 24 volts. A few peeps said fill it to you cant fit anymore but I want the real answer please.
 
As far as the NEC is concerned as many as you can stuff in the pipe.

Check your job specs they will likely have limits.

The specs may even limit you to two 90s instead of the NEC four.
 
Dean83169 said:
I was curious as to the method of figuring out how many cat 5 wires to fit inside a piece of EMT. Does the standard pipe fill follow the same rule or not since its under 24 volts. A few peeps said fill it to you cant fit anymore but I want the real answer please.
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A cable is treated as one conductor and can take up to 53% of the cross-sectional area of a raceway, two conductors up to 31% and three or more can take up to 40%. A nipple (24" or less in length) can have one or more conductors take up to 60% as per Table 1 Chapter 9. (Art. 358.2 allows cables within EMT)

Find the diameter of Cat 5 from the manufacturer's web site and to convert diameter to square inches, square the diameter and multiply by .7854. Once you find the sq. inches, check out Table 4 EMT and select the trade size conduit you're using and the appropriate % column and you're home free.:)

edited: OOPS! I just read 800.110, 820.110 which allow unlimited conduit fill. I don't see a similar provision at Art 830.133(A)(1), though.
 
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wbalsam1 said:
A cable is treated as one conductor and can take up to 53% of the cross-sectional area of a raceway,
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Yes, we can do that or if we consider that Cat 5 is likely to be covered by Article 800 we can ignore that.

Check out 800.110 Exception.

Conduit fill restrictions shall not apply
 
wbalsam1 said:
I don't see a similar provision at Art 830.133(A)(1), though.
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It does not need an exception as Article 830.133 does not require the raceway to be installed per chapter 3 as 800.110 does.:)
 
iwire said:
It does not need an exception as Article 830.133 does not require the raceway to be installed per chapter 3 as 800.110 does.:)
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Not only do I learn from you, Bob, but your avatar is of my favorite movie actor of all times. Westerns or drama, Clint's the man. :) :cool:
 
Bob,
As far as the NEC is concerned as many as you can stuff in the pipe.
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Article 725 and not 800 applies to computer cables. 725.3(A) makes the wire fill rules mandatory for CAT 5 cable.
Don
 
Cat 5 can not take much tension while pulled.The people to consult are the IT.While 4 or 5 might easily fit a lot depends on them and lenght as well as 90's.In a normal (what ever normal is ) stub of 10 feet with 1 90% they might allow 4 cat 5e but its up to them.Might be smart to go to 1 inch
 
So which article applies to Cat5 cabling, 725 or 800? Because I see 800.110 exception can we all agree on this yet?
 
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Dean83169 said:
So which article applies to Cat5 cabling, 725 or 800? Because I see 800.110 exception can we all agree on this yet?
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725.3 refers to Chapter 3 and 725.3(A) refers to 300.17. I think the fill tables apply. :)
 
Dean,
So which article applies to Cat5 cabling, 725 or 800?
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Most code authorties and the handbook say that CAT 5 is under Article 725.
From the handbook comentary...
The installation requirements for the low-voltage wiring of information technology equipment (electronic data processing and computer equipment) located within the confines of a room that is constructed according to the requirements of NFPA 75, Standard for the Protection of Information Technology Equipment, are not covered by Article 725. Low-voltage wiring within these specially constructed rooms is covered in Article 645.
Also, if listed computer equipment is interconnected and all the interconnected equipment is in close proximity, the wiring is considered an integral part of the equipment and therefore not subject to the requirements of Article 725. If the wiring leaves the group of equipment to connect to other devices in the same room or elsewhere in the building, the wiring is considered ``wiring within buildings'' and is subject to the requirements of Article 725.
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Don
 
How many cat5s are you thinking? It has been my experiance that cat5 pulls are A-L-O-T more difficult then standard cables. I don't know if it is the jacketing or the what but it drags in a pipe. I don't think the fill tables for CCC's are the issues related to cat5, where CCC's have more pull strength,they heat up to much higher temps. I would be much more concerned with dammaging the cat5 by pulling to hard. On a side note I have seen 2000 pair phone cable so I don't think heat is the issue.
 
don_resqcapt19 said:
Bob,

Article 725 and not 800 applies to computer cables. 725.3(A) makes the wire fill rules mandatory for CAT 5 cable.
Don
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don_resqcapt19 said:
Dean,

Most code authorties and the handbook say that CAT 5 is under Article 725.
From the handbook comentary...
Don
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Don I am aware of this, and have even discussed it with you before, but I don't think it is as clear cut as you make it sound. :)

In my experience, at least in this area (as backed up by Hal's experience in CT) Cat 5 is installed under one of the 800 articles.

That said I can also agree that 725 can apply.
 
Bob,
I just don't see any way that you can fit computer communications systems into the scope of Article 800.
800.1 Scope
This article covers telephone, telegraph (except radio), outside wiring for fire alarm and burglar alarm, and similar central station systems; and telephone systems not connected to a central station system but using similar types of equipment, methods of installation, and maintenance.
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That being said CAT 5 is not an exact match to the scope of Article 725 either.
725.1 Scope
This article covers remote-control, signaling, and power-limited circuits that are not an integral part of a device or appliance.
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I guess I can say that CAT 5 is clearly not covered by Article 800, but is not clearly covered by Article 725. The basis for putting it under Article 725 is the word "singnaling" in the scope.
Don
 
When I was designing Cat-5 installations, the manufacturer required that the cable be subjected to a maximum of 25# pulling tension. This keeps your conduit fill VERY low. Consult the cable manufacturer for fill recomendations, I believe you will find them much lower than the NEC requirements.
 
Please help me out here with all this talk about cat #5

What I would like to know is how you got the first four cats in the pipe.

I would think that by the time you got the first one or two in the pipe you would look like you had been in a fight with blender.
 
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