Data wiring Article 725 or chapter 8

[26T]

recently I read an article about Data wiring from a reputable magazine. The auther repeatedly reffered to Data wiring as class 2 wiring and is not part of Article 800. does anyone else besides me think he might be wrong?

 

[hbiss]

I've heard this before and he is wrong.

Art 645 deals with Information Technology Equipment.

645.6 Cables not in Information Technology Rooms
Cables extending beyond the information technology equipment room shall be subject to the applicable requirements of this Code.

FPN: For signaling circuits refer to Art 725; for fiber optic circuits refer to Art 770; and for communications circuits refer to Art 800. For fire alarm systems refer to Art 760.

Network data cables are clearly communications circuits the same as telephone and as such Art 800 applies.

-Hal

 

[don_resqcapt19]

The code is not clear, but it is my opinion that data wiring is covered by Article 725 and not by 800.

 

[chris kennedy]

The code is not clear, but it is my opinion that data wiring is covered by Article 725 and not by 800.

Why would you think this, reading 725.1 and 800.1 I would tend to agree with Hal.

 

[don_resqcapt19]

The following is from a document recently published by the Communications Cable and Connectivity Association, Inc.

Data wiring (class 2 wiring) is covered by Article 725 and some computer room installations are covered by Article 645. These Articles are permitted to (and do) modify the general wiring rules in Chapters 1 through 4; however they are not permitted to modify the wiring rules for communications installations without a reference from Chapter 8; this is significant for installations of communications equipment in a computer room where Article 645 is applied to the IT equipment but not the communications equipment.

 

[hbiss]

The code is not clear, but it is my opinion that data wiring is covered by Article 725 and not by 800.

Ok. If that were true, is premises data wiring class 1, CL3 or CL2 and how would you tell? Where does it say that premises data wiring is CL2??? Nowhere.

If 725 really did govern then data wiring would need to be class 1 because there is no indication of the wiring method required or power source class for the ethernet ports marked on the back of computer NICs, switches, routers, etc. That's because there is no power involved unless you are using POE.

I think the FPN for 645.6 makes it pretty clear.

-Hal

 

[Smart $]

The first thing here is you have to define data as used for the circuit. Data can be as simple as binary encoding, such as exhibited by an on-off switch, to the more elaborate digital and analog encodings.

The definition of communications circuit in 800.2 includes data, but goes on to state the extends is from the communications utility to and including the customer's communication equipment. If the data wiring does not extend the communications utility services, it is not governed by Chapter 8. The FPN's to 800.1 seem to indicate this (for they are not enforceable), but 800.133 makes it good as gold.

Ultimately, without defining the data itself and whether it will be transmitted via a communications utility, it can fall under Chapter 8 or other articles... or both as exemplified in 800.133(A)(1)(b). But to say data wiring is CL2 and does not fall under Chapter 8 requirements is CLEARLY wrong.

 

[don_resqcapt19]

Every class I have been to has called computer/data wiring Article 725 wiring.

I see nothing in 645.6 that even addresses the issue of what article applies to the computer/data wiring.

I don't see anything that makes calling computer/data wiring Article 725 wiring "clearly wrong".

The quote I posted is from the computer/data wiring industry and they call it Article 725 wiring and that is good enough for me.

 

[Smart $]

Every class I have been to has called computer/data wiring Article 725 wiring.

I see nothing in 645.6 that even addresses the issue of what article applies to the computer/data wiring.

I don't see anything that makes calling computer/data wiring Article 725 wiring "clearly wrong".

The quote I posted is from the computer/data wiring industry and they call it Article 725 wiring and that is good enough for me.

If the wiring permits the connected computer to access the internet, would you classify that wiring under 725 or 800?

 

[hbiss]

Every class I have been to has called computer/data wiring Article 725 wiring.

Well, they are wrong.

I see nothing in 645.6 that even addresses the issue of what article applies to the computer/data wiring.

Didn't I provide the FPN above?

I don't see anything that makes calling computer/data wiring Article 725 wiring "clearly wrong".

If you understand 725 you will know that it pertains to wiring and circuits carrying voltage and current other than power. Communications wiring does not carry any appreciable voltage or current and neither does data wiring. To say that wiring has to "extend from a communications utility service" otherwise it is Art 725 isn't definitive. All telephone wiring, even that after a PBX can be said to connect with the utility. Likewise nearly all data wiring connects with the internet so there is your reason for applying Art 800. The deciding factor as to whether 725 or 800 applies should be the level of voltage and current present or the lack of, and that is a mistake on the part of the NFPA.

The quote I posted is from the computer/data wiring industry and they call it Article 725 wiring and that is good enough for me.

You're kidding right? The pocket protector crowd is hardly the people I would expect to know anything about or to interpret the NEC. I'm insulted that you would take their opinion over the combined knowledge of the people on this board.

-Hal

 

[26T]

Now you Know

Now you Know

Thank you all for your comments. I do not feel so bad that I was confused by the article. don sited the exact article that confused me. I called the local AHJ and he said it was absolutly 800 and then I called the regional supervisor and he said it was 725. so there you have it.

 

[don_resqcapt19]

Hal,
You say my instructors have been wrong, but that is just your opinion. There is nothing definitive in the NEC that makes it clear what Article applies.

The FPN does not give any information that applies to this discussion. For it to apply here, it would have to define signaling and communications circuits and it does not do that.

I find my source to be authoritative for this discussion. They are the people who actually install these systems.

I will research the scope statements when I have time, but probably after the holidays. I am sure that the original scope of 800 was only voice communications and will have to be convinced that has been changed by the CMP.

For what it is worth, the handbook commentary says that the data system within a building is an Article 725 installation. However that statement is just opinion, just like yours or mine.

Although information technology equipment systems are often used for or with communications systems, Article 800 does not cover wiring of this equipment. Instead, Article 645 provides requirements for wiring contained solely within an information technology equipment (computer) room. (See 645.4 for a description of the type of information technology equipment room to which Article 645 applies.) Article 725 provides requirements for wiring that extends beyond a computer room and also covers wiring of local area networks within buildings. Article 760 covers wiring requirements for fire alarm systems.
In some cases, telephone system wiring is also used for data transmission; this use is covered by Article 800.

The last part of the handbook commentary clouds the issue, but in general the authors of the handbook say that the data installation is covered by 725.

 

[hbiss]

I find my source to be authoritative for this discussion. They are the people who actually install these systems.


And they get their information from the same sources we do- so what they say is no more than opinion also.

I've always said that the NEC has a lot of work to do in the areas of technology and this points out just one instance where they fall flat on their face. It takes forever to make changes where there are obvious discrepancies and the three year code cycle is a lifetime when it comes to new technology. By they time they get around to include something, it's already obsolete.

-Hal

 

[LarryFine]

I find my source to be authoritative for this discussion. They are the people who actually install these systems.

That certainly hints at "It must be right; that's how we've always done it."