Ethernet

Status
Not open for further replies.

jumper

Senior Member
I say yes, but many will disagree. Don, where is that cable manufacturers article?

725.121(4) Listed information technology (computer) equipment
limited-power circuits.

Informational Note: One way to determine applicable requirements
for listing of information technology (computer)
equipment is to refer to UL 60950-1-2003, Standard for Safety
of Information Technology Equipment. Typically such circuits
are used to interconnect information technology equipment for
the purpose of exchanging information (data).
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Eric,
That article you cited appears to be talking about Power Over Ethernet. I had one that said that the Ethernet cables were an Article 725 installation even where they do not power equipment. It was posted here, but I have not looked for it in some time.

The code is not completely clear on this. There are "experts" that say 725 is the governing article and others that say it is 800. I don't know of anyone who says 830 applies to Ethernet cables.
 

jumper

Senior Member
Eric,
That article you cited appears to be talking about Power Over Ethernet. I had one that said that the Ethernet cables were an Article 725 installation even where they do not power equipment. It was posted here, but I have not looked for it in some time.

The code is not completely clear on this. There are "experts" that say 725 is the governing article and others that say it is 800. I don't know of anyone who says 830 applies to Ethernet cables.
Ack. You lost the article. My whole argument was based on it. Phooey!!!!
 

erickench

Senior Member
Location
Brooklyn, NY
Okay, I'm flying down to Nashville, Tennessee tomorrow for a job interview with Schneider Electric. The position is for Application Engineer and I'll be doing Powerlogic meters in the field. These meters all have ethernet, RS-232/485 ports for connection to cables. For the immediate connection to these meters would NEC 725 or NEC 800 apply?
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
Found a graphic

That's a communications circuit WITH a CL2 circuit. Says so right there at the top.

The answer to the OPs question is that there is no answer according to the NEC. It's just not mentioned so the question of where data or ethernet wiring is covered is open to debate and it has been debated here several times. IMO it should be covered by Art 800. Unfortunately much of the LV articles need new input and revising because they are either not in step with current technology or whoever is responsible for writing them doesn't know the trade.

-Hal
 

__dan

Senior Member
I think one of the criteria is what the wire is used for, the application. Using cat 5 for power monitoring or power control equipment comm. is clearly article 725. Using the same cat 5 in a different application could be article 800.

Good luck with the job app.
 

kwired

Electron manager
Location
NE Nebraska
I think one of the criteria is what the wire is used for, the application. Using cat 5 for power monitoring or power control equipment comm. is clearly article 725. Using the same cat 5 in a different application could be article 800.

Good luck with the job app.
If that power monitoring Cat 5 cable is plugged into a network that also provides communications to otherwise article 800 applications how is it not also an article 800 application?

If it is power monitoring system but only connects to power monitoring equipment and not to some general purpose type network then it may not be an article 800 application.


What I am saying is if the power monitor cable is plugged into the same network that the office computers use for typical communications then isn't it all the same system?
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
I think one of the criteria is what the wire is used for, the application.
No, it has nothing to do with what the wire is being used for and all to do with what it is carrying voltage and current wise. An ethernet connection between power monitoring equipment is no different than an ethernet connection between control equipment for a nuclear plant which is no different than an ethernet connection between two computers in someones home.

These meters all have ethernet, RS-232/485 ports for connection to cables. For the immediate connection to these meters would NEC 725 or NEC 800 apply?
Clearly Art 800 but that's my opinion based on the intent of the article and the characteristics of these data connections since you won't find any reference to "ethernet", "RS-232 or RS-485 in the Code. None carry any appreciable amounts of voltage or current and are clearly communications circuits.

-Hal
 

__dan

Senior Member
What the cable plugs into.

800.18, communications equipment shall be listed in accordance with 800.170 as telcom equipment.

725.1, If the cable plugs into power monitoring equipment, it is on the load side of power distribution equipment. There is some mixing of power, class 1, class 2, class 3, associated with the utilization of the equipment. There is a lot more going on with the equipment beyond solely communication. Is the equipment listed as telcom only or listed as power supply and distribution with an accessory communication and control feature ?

There is some overlap between 725 and 800. Outside comm circuits look definitely art 800. I'm looking for the reference, I recall something about if an art 725 building control wire shared a cable tray with art 800 comm circuits, art 800 would apply.

There are layers to the comm network. Base layer, the power monitoring devices communicate to other same system devices, multiplexors, routers, traffic switches, and run stand alone on a PC in the Windows operating system. Next layer is system integration into a BAS, building automation system, running over that network for display on a PC in the BAS software as a software module . The BAS is a lot of art 725 class 2 running everywhere, controlling motors, receiving alarms. There is some standard ip network protocol comm paths over cat 5, with web browser access, however they should be air gapped to the other building network cabling for security purposes. Anyone with a web browser, web address, password, could gain full access to the BAS.

The point where the cat 5 plugs into primarily power distribution equipment with a monitoring device feature, that I would say is art 725. The protocol could be standard ip and the data packets may travel successfully over a widespread ip network. The point where the cable carrying that data packet traffic plugs into solely listed per 800.170 telcom equipment, routers, that could well be art 800 cabling.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
It probably needs its only article. Maybe someone is working on a new article for 2014. At the least there should be some proposals submitted for 2014 to clearly state what article applies. Proposals are due the first Friday in November of this year.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
What the cable plugs into.

800.18, communications equipment shall be listed in accordance with 800.170 as telcom equipment.

725.1, If the cable plugs into power monitoring equipment, it is on the load side of power distribution equipment. There is some mixing of power, class 1, class 2, class 3, associated with the utilization of the equipment. There is a lot more going on with the equipment beyond solely communication. Is the equipment listed as telcom only or listed as power supply and distribution with an accessory communication and control feature ?

There is some overlap between 725 and 800. Outside comm circuits look definitely art 800. I'm looking for the reference, I recall something about if an art 725 building control wire shared a cable tray with art 800 comm circuits, art 800 would apply.

There are layers to the comm network. Base layer, the power monitoring devices communicate to other same system devices, multiplexors, routers, traffic switches, and run stand alone on a PC in the Windows operating system. Next layer is system integration into a BAS, building automation system, running over that network for display on a PC in the BAS software as a software module . The BAS is a lot of art 725 class 2 running everywhere, controlling motors, receiving alarms. There is some standard ip network protocol comm paths over cat 5, with web browser access, however they should be air gapped to the other building network cabling for security purposes. Anyone with a web browser, web address, password, could gain full access to the BAS.

The point where the cat 5 plugs into primarily power distribution equipment with a monitoring device feature, that I would say is art 725. The protocol could be standard ip and the data packets may travel successfully over a widespread ip network. The point where the cable carrying that data packet traffic plugs into solely listed per 800.170 telcom equipment, routers, that could well be art 800 cabling.
Wow. You are so confused and we are getting off topic here. The original question was "Does anyone know if the installation of ethernet cables such as category 5E are covered by NEC 725?"


As I have said before, the governing Article depends on if and to what extent the cable carries voltage and current. Ethernet is a standard and it does not involve any appreciable voltage and current in the transmission of data over a connecting cable. As long as the transmission meets the ethernet protocol it is a COMMUNICATIONS cable. IT DOESN'T MATTER what the equipment is that it is connected to or even if the cable is CAT5.

Further, CAT5 is just wire. It is not ethernet unless it connects two pieces of equipment that use the ethernet protocol. So don't be confused there. Since CAT5 has become the "universal" LV cable it is being used for everything and anything LV and that certainly would include CL2 Artical 725 applications.


Now, if the equipment uses the POE (power over ethernet) protocol to supply power to connected equipment over the same cable as data THEN there is a Class 2 component and THEN it will fall under Art 725. That's what that illustration was about.


And no, I don't think data cabling needs a separate article, just people on code panels who know what it is so that it will be included within the appropriate articles. I've said it many times before, LV and communications is a completely different trade where you often have to understand how something works before you can install it (or apply a Code article).

-Hal
 
Last edited:

__dan

Senior Member
I did not feel confused, even after reading your reply. I have a license allowing me to apply the code.

What I tried to convey, look at the equipment UL listing. Power distribution monitoring equipment may say "listed class 2" on the boards or devices and so imo art 725 would apply. If you find the UL label says "listed telecommunications equipment" then imo art 800 applies. The governing authority looks like the UL listing and the manufacturer's specs.

Between the articles, the biggest applicable difference looks like the listing of the cables, ie., if the cable says listed CL2 - CL3, or listed CM.

The Powerlogic equipment speciified in the thread, I would make one phone call to the manufacturer and ask for the UL listing requirement. It is probably listed as power distribution equipment with power limited comm circuits. The device is probably available with and without an ethernet port. The ethernet port may be an optional accessory and not the sole purpose or function of the device. It may support a variety of standard and proprietary BAS network comm protocols, interconnection methods, in addition to connecting to devices that sit right on or clamp right on, the dangerous high power level bus.

I could take any piece of thhn and wire is wire is wire. However, based on the terminals it is connected to several different chapters and hundreds of code articles could apply. It is hot, neutral, EGC, GEC, feeder, branch circuit, motor, transformer based on what the wire is connected to.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
What I tried to convey, look at the equipment UL listing. Power distribution monitoring equipment may say "listed class 2" on the boards or devices and so imo art 725 would apply.

I have a license allowing me to apply the code.

:eek: A license is no guarantee that the holder understands all of the Code, only that they have passed a test that is representitive of what is in the Code book. Matter of fact a test taker could not even bother to answer many LV questions and still pass.

Equipment that utilizes Class 2 circuits as inputs or outputs or supplies power IN ADDITION TO an ethernet port for the transmission of data does not make the ethernet ports or wiring Class 2 unless it is POE! Ethernet can never be CL2 unless it is POE!


-Hal
 
Status
Not open for further replies.
Top