Class 1, Class 2 circuits.

[tom baker]

To OPs question:

No, don’t classify it. The motor load is chapter 4 special equipment which modifies chapter 3 general wiring.

Classes 1-3 are for power limited circuits under chapter 7. Review section 90 in NEC. Chaptersi 1-3 cover general requirements. Chapters 4-6 cover special situations that modify chapters 1-3. Chapter 7 takes an entirely different approach. You IGNORE everything in chapters 1-6 unless chapter 7 specifically calls for it. As a general rule you cannot mix chapter 1-3 and chapter 7 wiring. As a general rule of thumb about the only loads you can mix are lighting loads.

Nothing OP describes falls outside general purpose wiring. It’s one thing when someone wants to run an Ethernet cable in a conduit with a couple lights. It’s quite another to be running it with power wiring and that’s what the rules captur

To OPs question:

No, don’t classify it. The motor load is chapter 4 special equipment which modifies chapter 3 general wiring.

Classes 1-3 are for power limited circuits under chapter 7. Review section 90 in NEC. Chaptersi 1-3 cover general requirements. Chapters 4-6 cover special situations that modify chapters 1-3. Chapter 7 takes an entirely different approach. You IGNORE everything in chapters 1-6 unless chapter 7 specifically calls for it. As a general rule you cannot mix chapter 1-3 and chapter 7 wiring. As a general rule of thumb about the only loads you can mix are lighting loads.

Nothing OP describes falls outside general purpose wiring. It’s one thing when someone wants to run an Ethernet cable in a conduit with a couple lights. It’s quite another to be running it with power wiring and that’s what the rules capture.

Right and Class 1 wiring can only be run with power wiring if its functionally related. Example would be start stop wiring in the same conduit as the power wiring to a motor

 

[DrSparks]

I find that a bit far fetched. While technically CAT5 is rated 300V, 22ga would make it good for about .7A in a multi-core cable. So assuming 277V max., that's less than 200W and even with LED, I don't think a 200W fixture would be much of a "high bay" light source. I also don't think you would find an AHJ that would allow it to be used for 277V, or even 120V for that matter. If they were thinking 48VDC to make is "low voltage", the current is the same, so now we are talking a 33W LED fixture...

The system I was referring to is 48 VDC. Not sure on the specifics. Or how many fixtures per run. I just remember each fixture accepts 2 CAT 5 cables in parallel.

Sent from my BE2028 using Tapatalk

 

[Strathead]

Sure it’s several code cycles old

OK, I will check the references, but it is still accurate.

 

[Dsg319]

class 1 control circuit. 120volt to a float back to a ice cube relay for start/stop operations. Would it be considered current carrying conductor, and be stuck with ampacity adjustments?

 

[petersonra]

class 1 control circuit. 120volt to a float back to a ice cube relay for start/stop operations. Would it be considered current carrying conductor, and be stuck with ampacity adjustments?

class 1 circuits are not required to have ampacity adjustments until you get 30 conductors in a raceway.

 

[cvillej17]

Until recently I hadn't run in to "power over ethernet" light fixtures. Now I have, and I feel that is a misnomer. It is merely power over a cable and connectors that are also used in ethernet applications. It has zero to do with ethernet.

That's not true. The control network is two way communication. The development of the technology is centered around not only lighting control, but also to bring data from the fixtures, or more precisely from sensors attached to the fixtures, back to a central server. The collected sensory data can be used for the display of environmental or electrical monitoring, and occupancy. Gunshots can be detected and relevant information sent directly to first responders instead of sorting through 1000s of 911 calls. The centralized servers can be stand-alone or the lighting system and it's data can be fully integrated with other building systems.
Highbays are not a problem. The LED arrays are segmented within the fixture so multiple drivers can be applied. Is that practical? The jury is still out, but it is possible and being implemented. On the most recent IEEE 802.3bt standard, 71 watts at the fixture x2 drives a highbay quite nicely.

Yes, I sound like an advertisement, but hey, someone has to pop in here to let you know it's the way of the future. Sorry I'm late to the party.

I mainly joined to see how the NEC is handling PoE lighting because customers are asking. It sounds like they're not doing a very good job, yet.

 

[petersonra]

I mainly joined to see how the NEC is handling PoE lighting because customers are asking. It sounds like they're not doing a very good job, yet.

The NEC does not need to "handle" POE. The code already deals with it. Any handling that needs doing is really upto the manufacturers. The NEC is a safety and installation code and POE is not anything special that it does not cover.

 

[hbiss]

Yes, I sound like an advertisement, but hey, someone has to pop in here to let you know it's the way of the future. Sorry I'm late to the party.

I mainly joined to see how the NEC is handling PoE lighting because customers are asking. It sounds like they're not doing a very good job, yet.

You are not late to the party. There have been threads in the past from people like you who think it's the best thing since sliced bread. That went nowhere.

The NEC includes CL2 and CL3 in Art 725. CL2 or CL3 is what power over ethernet is. Low voltage power on communications cables is certainly nothing new and doesn't require a separate Article just for every application that comes along.

-Hal

 

[GoldDigger]

I guess it all comes down to whether or not the UL listing standards require the Class 2 or Class 3 markings. The NEC does not appear to require it.

 

[don_resqcapt19]

class 1 circuits are not required to have ampacity adjustments until you get 30 conductors in a raceway.

I don't recall that code rule. Can you give me the section?

I though the rule was no derating for Class 1 as long as the load current does not exceed 10% of the conductor ampacity, and where the current does exceed 10%, then the standard ampacity adjustments apply.

 

[wwhitney]

I guess it all comes down to whether or not the UL listing standards require the Class 2 or Class 3 markings. The NEC does not appear to require it.

Well, an applicable excerpt from UL 1310 "Standard for Class 2 Power Units" is below as an image.

But doesn't the exception that petersonra highlighted allow for a product listed to another standard, which happens to provide the proper limited energy levels, to be used as a Class 2 or Class 3 power source?

Cheers,
Wayne

 

[cvillej17]

The NEC does not need to "handle" POE. The code already deals with it. Any handling that needs doing is really upto the manufacturers. The NEC is a safety and installation code and POE is not anything special that it does not cover.

Got it. From what I read on other threads, there was some discussion about 800 vs. 725 and it was unclear when I started reading (at least to me) which article covered PoE lighting, specifically. 800 covers data and 725 covers the power, right? I'm new to the NEC - my background is mostly system commissioning (access control, lighting control, networks), not design and installation. The help is appreciated.

 

[petersonra]

Got it. From what I read on other threads, there was some discussion about 800 vs. 725 and it was unclear when I started reading (at least to me) which article covered PoE lighting, specifically. 800 covers data and 725 covers the power, right? I'm new to the NEC - my background is mostly system commissioning (access control, lighting control, networks), not design and installation. The help is appreciated.

800 covers data provided by the utility upto the point of connection (more or less). Ethernet is a class 2 circuit. Poe is either class 2 or 3.

 

[cvillej17]

You are not late to the party. There have been threads in the past from people like you who think it's the best thing since sliced bread. That went nowhere.

The NEC includes CL2 and CL3 in Art 725. CL2 or CL3 is what power over ethernet is. Low voltage power on communications cables is certainly nothing new and doesn't require a separate Article just for every application that comes along.

-Hal

Whether it's the best thing out there depends on the application, though I get your point. It probably went nowhere because it's not very well understood. As you know, PoE is not new, but the lighting application is more recent and it's being adopted rapidly. I doubt it will overtake AC power in my lifetime as an infrastructure, but I see how it could. If the PoE manufacturers get their acts together and talk about it as a solution instead of scaring everyone away with the nerdy details, it might gain some traction. The only way it will take off is if the market demands it, and right now it seems like smoke and mirrors.
I've seen in other threads where you mention it's probably developed by IT guys, and you are exactly right. You're also right when you say they want to push traditional AC out of the way. That's a BIG problem for PoE lighting. Lighting designers don't understand it and GCs and ECs don't know how exactly it fits in a construction process. It's still just a tiny sliver of the overall lighting industry, but I don't see it going away.

 

[petersonra]

I don't recall that code rule. Can you give me the section?

I though the rule was no derating for Class 1 as long as the load current does not exceed 10% of the conductor ampacity, and where the current does exceed 10%, then the standard ampacity adjustments apply.

I think you are right. No idea where I came up with the 30 conductor thing.

725.51 Number of Conductors in Cable Trays and Raceway,
and Ampacity Adjustment.
(A) Class 1 Circuit Conductors. Where only Class 1 circuit
conductors are in a raceway, the number of conductors shall be
determined in accordance with 300.17. The ampacity adjustment
factors given in 310.15(B)(3)(a) shall apply only if such
conductors carry continuous loads in excess of 10 percent of
the ampacity of each conductor.

 

[Strathead]

That's not true. The control network is two way communication. The development of the technology is centered around not only lighting control, but also to bring data from the fixtures, or more precisely from sensors attached to the fixtures, back to a central server. The collected sensory data can be used for the display of environmental or electrical monitoring, and occupancy. Gunshots can be detected and relevant information sent directly to first responders instead of sorting through 1000s of 911 calls. The centralized servers can be stand-alone or the lighting system and it's data can be fully integrated with other building systems.
Highbays are not a problem. The LED arrays are segmented within the fixture so multiple drivers can be applied. Is that practical? The jury is still out, but it is possible and being implemented. On the most recent IEEE 802.3bt standard, 71 watts at the fixture x2 drives a highbay quite nicely.

Yes, I sound like an advertisement, but hey, someone has to pop in here to let you know it's the way of the future. Sorry I'm late to the party.

I mainly joined to see how the NEC is handling PoE lighting because customers are asking. It sounds like they're not doing a very good job, yet.

I stand by my statement “power over Ethernet” implies to me that the power and the Ethernet are injected together and run through the cables together, when in fact even for all the functions you listed, Ethernet connects communications to power supplies and then the power supplies route power and Ethernet to a set of lights.

 

[petersonra]

I think most people are going to find whatever sensors are connected to the lights are probably not worth whatever they paid for them. Better to focus on reliable lighting and forget the fancy stuff no one needs and adds extra cost and complexity. It can still be Class 2 or 3 and not have any communications mucking up things.

The problem is to make the communications even minimally useful is going to require software, programming, and configuration that will add substantially to the overall cost. Plus someone is going to have to assign all the IP addresses, etc. Not a simple task.

 

[cvillej17]

I stand by my statement “power over Ethernet” implies to me that the power and the Ethernet are injected together and run through the cables together, when in fact even for all the functions you listed, Ethernet connects communications to power supplies and then the power supplies route power and Ethernet to a set of lights.

Maybe I wasn't clear enough, then. The communication rides on the same wires that the DC power uses, but it is network communication protocols (frames, packets) that transfer the data between the nodes, the switches and the server.

 

[petersonra]

Maybe I wasn't clear enough, then. The communication rides on the same wires that the DC power uses, but it is network communication protocols (frames, packets) that transfer the data between the nodes, the switches and the server.

Poe uses two pair for data and two pair for power.

 

[cvillej17]

I think most people are going to find whatever sensors are connected to the lights are probably not worth whatever they paid for them. Better to focus on reliable lighting and forget the fancy stuff no one needs and adds extra cost and complexity. It can still be Class 2 or 3 and not have any communications mucking up things.

I'd go even further and say that most people wouldn't look at sensors at all if the electrical code didn't require them. That being said, a PoE lighting system is far easier to commission on a project than something like a Lutron Quantum system. Lutron's system is great, but it's extremely complex and requires extensive knowledge and training for the EC, the commissioning agent, and the end user. Hubbell, Crestron, Marlin, and others are all the same - exceptionally complex.
Sure, PoE lighting is "fancier" than traditional lighting. It's different and it can do more with less than even the most complex stand-alone AC control systems. That doesn't make it more expensive across the board. Depending on what the customer wants it can be far less expensive, but it depends on the application. It's horrible for the budget of a relamp or fixture swap. You can get more than 90% of the benefit of LEDs on an existing system by swapping fluorescents and incandescents with LEDs.

The problem is to make the communications even minimally useful is going to require software, programming, and configuration that will add substantially to the overall cost. Plus someone is going to have to assign all the IP addresses, etc. Not a simple task.

The commissioning is significantly easier (and therefore cheaper) than a comparable AC control system. I've done both. PoE is easier. I commissioned an expo hall that had Lutron ballasts individually powering all 8000+ 8' T5 lamps (obviously several years ago). Commissioning that took weeks because I had to find and address each ballast. They've updated to control LED lamps, but the process is still the same. On PoE, addressing would've been done as soon as the driver received power from the network because the server assigns addresses automatically.