Wire size and pipe fill limits

[LarryFine]

Can anybody say which article it falls under ?

Article 800

How does Article 800 apply? Computer wiring is not in the scope of the article.

IMO that would depend entirely on what it is being used for. It may be 800 or 725.

Data wiring is not specifically mentioned in the NEC other than data wiring that carries power also.

I think that you can make a case that computer cabling is Article 725...

The NEC doesn't define "data wiring", perhaps that is a subject for a revision.

There is no (in the normal sense) current or voltage present in a data circuit. However, voice wiring can have in excess of 50 volts present and is classfied as a communications circuit under Artical 800.

What about Article 830? From the '02 NEC:

830.1 Scope. This article covers network-powered broadband communications systems that provide any combination of voice, audio, video, data, and interactive services through a network interface unit.

 

[iwire]

What about Article 830? From the '02 NEC:

Good question.

I am not sure but I thought that was addressing systems using coax not Cat 5E as the OP was asking about.

 

[H.Auto]

And Sat TV is?

And Sat TV is?

I'm wondering now if all those Comcast guys have to be EC since there is voltage on the coax?

 

[Jpreverso]

Is this legal or am I confused

Is this legal or am I confused

Ive been wrong before plenty of times, but if I under stand the situation correctlly the cat 5 was coming from the patch pannel out to a device some where, so whoudn't 830.3 (D) (1) refrence you back to to 800. Where then you would be refrenced all over the chapter until finally 800.110. As long as the cabel is plenum rated and the pipe its in is installed in accordanence w CH 3.

 

[tom baker]

Its not article 830, thats for a data cable that is used by providers to the structure.
Mike Holts material states that Art 725 applies to computer network wiring, but if the same cable has telephone then Art 800 applies. Computer network power supplies are Art 725 Class 2. Take a look at your network hub or switches wall wart.

 

[Jpreverso]

I did com for like six week as a first year so im not an expert but 830 sounded like the right place to start code serching to me. At article 830.3(d)(1) Instillations of comm circuits- Article 800

so i went to 800 800.110 RaceWays For Com Wires and Cables at the bottom of the article there is an Eception "Coduit fill restriction shall not apply." As long as The pipe is either ENT or installed in accnance w/ ch3 I assume its EMT but legal pur Ch3. The cat5 need to be Plenum rated. You cant have any coax, CATV or fa, in the pipe with it....... I work for a company that always subs the low voltage out, I havent had to mess with it Im baseing this all off of 830.3 (D) (1) then 800.100 That has the exception with it and also refrences to 800.182, Ch 3, 362.24 -56 I cant seem to find where i read that the com needed to be in the pipe buy its self.
But by all means check me dont take my word for it . It all came from 2005 Code, i just never run that stuff. If you dont have a code book tonight let me know what you get out of it. Josh

 

[hbiss]

Computer network power supplies are Art 725 Class 2. Take a look at your network hub or switches wall wart.

Nice try but no. The wall wart only provides power to the hub or switch for it's operation. There is no power on the cables extending from the hub or switch to the related computers or other equipment, only data.

Mike Holts material states that Art 725 applies to computer network wiring...

Looks like Mike is only repeating the information given in the handbook.

As long as the cable is plenum rated and the pipe it's in is installed in accordance w CH 3...

I think we are getting off track here. The NEC does not say that cable in pipe needs to be plenum rated.

-Hal

 

[Jpreverso]

maybe this will help

maybe this will help

I havnt figured it out yet but I belive the tabels on 70-637 through 70.639 will help you GET R DONE if you didnt all ready know about they

 

[Jpreverso]

one last thought

one last thought

To me it looks like i spoke to soon on my last post I think the tables on 70- 638 - 70 639 are to do a diffrent calculation on a class 2 or 3 circuit. It looks like artice 725.3 (A) is the artice that send you over to article 300.17
Number and size of Conductors in race way.Then a FPN note that to me says pick your race way it just lists a bunch , so ill go emt. I have always been told 9 curent caring conductors in a pipe so thats what i figured here. 356.22 Emt them sends us to Table 1 chapter 9. The chart that i belive allready has the calculation done for us. My question for you is the cat 5 has 4 twisted pairs inside. so each cabel has its own nutrual if thats what you want to call it wouldnt that open up 310.15 (B) (2) (a) I know it says you cant do it with a multi cabel but thats just because more than one phase coming back on a neutral puts more load on it. That might not fly on a data device but the phone . Just a Thought Josh

One more question were you planing on running CI cabel in a diffrent pipe. If the heard it feed is considerd part of a critical system its supposed to last longer if a fire breaks out . Have a happy 4th

 

[iwire]

Mike Holts material states that Art 725 applies to computer network wiring...

Looks like Mike is only repeating the information given in the handbook.

Or Maybe Mike is correct.

 

[hbiss]

Unless he requested a clarification from the code panel he is working with the same information we have.

-Hal

 

[iwire]

Unless he requested a clarification from the code panel he is working with the same information we have.

-Hal

I agree.

The information we have at hand is ambiguous at best, I don't see anything that rules out either 725 or 800 other than personal preference.

It is certainly easer if we say it an 800 installation as that removes most of Chapter 3.

If your AHJs are fine with 800 than great for you.

I am not pretending to know the answer, I wish I did.

The little bit of this type of work I have done has been under job specs that I suspect exceed the requirements in either 725 or 800.

Oh the other day I hooked up an electric door operator, the factory power supply was a wall wart with Cat 3 from that to a phone jack and the closer it self had a phone cord on it that plugged into the phone jack I mounted at the door frame. That was definitely a 725 installation.

You can see it here

 

[sgobeli]

Rcdd

Rcdd

While the description of Article 800 is correct. Article 90 - Scope states the NEC covers the installations of electrical conductors, so we have to assume Cat 5 cables are covered by the NEC. I use notes 5 and 9 of table 9 of the NEC and caluculate the allowable fill. The diameter of cables can usually be found on the manufacturers web site.

Steve