What makes a Lighting System a System?

[al hildenbrand]

From the 2005 NEC

411.2 Definition

Lighting Systems Operating at 30 Volts or Less. A lighting system consisting of an isolating power supply operating at 30 volts (42.4 volts peak) or less under any load condition, with one or more secondary circuits, each limited to 25 amperes maximum, supplying luminaires (lighting fixtures) and associated equipment identified for the use.

Does the luminaire have to be supplied by the manufacturer of the isolation power supply?

That is, is the luminaire required to be part of the "Lighting System" in some discernable way beyond being a low voltage luminaire?

 

[roger]

Re: What makes a Lighting System a System?

Hello Al, I would think it is refering to a system in description rather than a manufacturers product.

PS, you caught me off guard posting under just "Al" the other day.

Roger

 

[pierre]

Re: What makes a Lighting System a System?

Mark Ode wrote an article about this. I believe it is in the Electrical Contractor Magizine.


Tom Baker... here is a good example of what you asked me about

 

[al hildenbrand]

Re: What makes a Lighting System a System?

Thanks, Pierre,

I found Mark C. Ode's July, 2001, article here.

Individually Listed low-voltage components could still be assembled to cover a large low-voltage lighting system, but would not be covered by Article 411.

This installation would be considered a Class 1 power-limited circuit and must comply with the requirements in Parts A and B of Article 725. The fixtures must comply with Article 410 and the wiring system must comply with Chapter 3.

The important point to remember about low-voltage lighting systems covered by Article 411 is that the lighting is Listed as a system, as opposed to low-voltage lighting that is assembled as component parts.

So, if I use a cord and plug connected 300 VA Malibu transformer like this one:

And I use the transformer to power Kichler luminaires, I am required to go to Chapter 3 wiring methods?

[ January 31, 2006, 07:05 AM: Message edited by: al hildenbrand ]

 

[pierre]

Re: What makes a Lighting System a System?

You are welcome.

Chapter 3 wiring methods only if you are installing the wiring inside of a wall/ceiling (wall/ceiling cavity) or through the wall. On the surface of the wall or outside the building, you can use other methods.

 

[George Stolz]

Re: What makes a Lighting System a System?

How can the NEC quote Al posted in his original question be seen as matching the answer Ode gave?

That just doesn't seem to jive.

So does the premises wiring system have to come out of a box as a factory-designed unit?

 

[ryan_618]

Re: What makes a Lighting System a System?

Originally posted by pierre:
You are welcome.

Chapter 3 wiring methods only if you are installing the wiring inside of a wall/ceiling (wall/ceiling cavity) or through the wall. On the surface of the wall or outside the building, you can use other methods.

I disagree. Chapter 3 wiring methods are required regardless, unless it is a class II power supply. Remember that this is a chapter 4 rule, and nothing modifies the general rules of chapter three in it. 90.3

 

[al hildenbrand]

Re: What makes a Lighting System a System?

Originally posted by ryan_618:
Chapter 3 wiring methods are required regardless, unless it is a class II power supply.

The 12V 300VA Malibu landscape lighting system isolating power supply pictured above, a ML300RTW is not labeled Class 2.

A boxed landscape lighting kit comes with a hank of "underground low energy circuit cable sunlight resistant 60?C 150V" two conductor cable with an "E" number that leads to UL Category Code ZMHX, Wire, Special Purpose. The bold quote above is stamped on the insulation of the hank every foot or so.

It looks kind of like SPT-3 cord. But it calls itself "cable".

I've not been successful in getting info about ZMHX from UL.com.

Can this wire be used at all on a deck?

 

[ryan_618]

Re: What makes a Lighting System a System?

But that would be part of the listed lighting system. I guess I should have been more clear on that part, my bad.

By the way, these cables are listed for outdoor use only.

 

[pierre]

Re: What makes a Lighting System a System?

411.4 Locations Not Permitted.
Lighting systems operating at 30 volts or less shall not be installed in the locations described in 411.4(A) and 411.4(B).
(A) Where concealed or extended through a building wall unless permitted in (1) or (2):
(1) Installed using any of the wiring methods specified in Chapter 3.

So, if installed on the wall surface where it is not concealed, it would not be required to use a Chapter 3 method.


I do agree that the black (it is mostly sold in black, sometimes in white) landscape stranded cable is not listed for use indoors.

[ February 01, 2006, 02:35 PM: Message edited by: pierre ]

 

[ryan_618]

Re: What makes a Lighting System a System?

But Pierre, this is a chpater 4 installation. What section gives you the permission to deviate from Article 300?

 

[al hildenbrand]

Re: What makes a Lighting System a System?

Originally posted by ryan_618:
What section gives you the permission to deviate from Article 300?

90.3 Code Arrangement
This Code is divided into the introduction and nine chapters, as shown in Figure 90.3. Chapters 1, 2, 3, and 4 apply generally; Chapters 5, 6, and 7 apply to special occupancies, special equipment, or other special conditions. These latter chapters supplement or modify the general rules. Chapters 1 through 4 apply except as amended by Chapters 5, 6, and 7 for the particular conditions.

Please note my bold italics and consider:

300.1 Scope
(A) All Wiring Installations This article covers wiring methods for all wiring installations unless modified by other articles.

And again, please note my bold italics and consider:

411.4 Locations Not Permitted
Lighting systems operating at 30 volts or less shall not be installed in the locations described in 411.4(A) and 411.4(B).

(A) Where concealed or extended through a building wall unless permitted in (1) or (2):

</font>

• <font size="2" face="Verdana, Helvetica, sans-serif">Installed using any of the wiring methods specified in Chapter 3</font>

<font size="2" face="Verdana, Helvetica, sans-serif">

"Concealed" is not permitted, therefore:

Article 100
Exposed (as applied to wiring methods). On or attached to the surface or behind panels designed to allow access.

"Exposed" hasn't been prohibited for Article 411 Lighting Systems, so I can install the Lighting System exposed (as applies to wiring method) with the wire in the box. . .the UL Category ZMHX power limited circuit cable ( a cable not in Chapter 3).

 

[al hildenbrand]

Re: What makes a Lighting System a System?

***Bump***

Comments on the Code logic, anyone?

 

[ryan_618]

Re: What makes a Lighting System a System?

I'm still not seeing it.

 

[al hildenbrand]

Re: What makes a Lighting System a System?

Originally posted by ryan_618:
. . .these cables are listed for outdoor use only.

Yes. And the transformer label states "Install Outdoors Only". And the luminaires state something to the effect "Use with 12 V Landscape Lighting Systems Only".

I probably haven't been clear, my apology.

For clarity's sake, I'm trying to consider one form of an Article 411 listed lighting systems operating at 30 V or less that I see a lot of, and that is Landscape Lighting Systems installed outside of buildings.

Besides the basic string of lights along the walkway, or lighting up the shrubs, I see this System worked into decks and other constructed items that are part of the "landscape" outside of the dwelling.

Please consider the deck below. Its framing is open underneath. The pot lifts out of the planter.

As I read Article 411, the Landscape Lighting System cable ZMXH supplied with the system can be stapled to the open framing.

If I cut the recessed light shown below into the railing, and fish the ZMXH cable to it, is the cable concealed?

I can still remove the light to get at the cable.

 

[ryan_618]

Re: What makes a Lighting System a System?

Hi Al. I think one of the problems that you and I are having is that we are thinking of two different types of low voltage lighting systems. You are thinking about "malibu" type lighting, and I am thinking of indoor lighting.

Here is a picture of a low voltage transformer of the type I am thinking of, which is 24 V, 600VA

And this is the reason that it needs to be in a chapter three wiring method.

This fire was on the secondary side of this transformer.

Now, regarding ARticle 411. The biggest issue that I have is that it doesn't address wiring methods. If this were not a "system" it would be a class 1 (Article 725) installation, becasue it is not renedered safe inherently by limiting the current to a safe value. Now, once it is a "system" with the luminaires and the transformer listed together, we go to Article 411. Article 411 doesn't modify the rules of Chapter 3, in my opinion. But this is where we seem to disagree.

 

[al hildenbrand]

Re: What makes a Lighting System a System?

Thanks for sharing the photos. And thank you for your ICC Newsletter article.

Setting my questions to the side for the moment to consider the visible information in your photos, I note from your article:

Originally posted by ryan_618:
The fire that I observed was started at a free air splice, . . .

Maybe the next step is to put AFCI protection that actually detects series arcs below 25 A in the secondary OCP device of the Article 411 isolation power supply?

 

[ryan_618]

Re: What makes a Lighting System a System?

Here is something I found from UL on the subject of Article 411 wiring methods:

3.2
Q.
Is there a cable Listed for low voltage lighting systems that can be fished in a wall or ceiling without installation in a Chapter 3 raceway?
A.
No, currently, UL does not List a specific stand alone cable intended for use in concealed locations in accordance with the requirements of Section 411.4 of the NEC? for Lighting systems operating at 30 volts or less.
Section 411.4 of the 2002 NEC? requires Chapter 3 wiring methods for concealed wiring. Chapter 3 covers wiring
methods for all wiring installations, unless modified by
Page
Questions and Answers from UL Meetings with Electrical Inspectors at the
IAEI 75th Jubilee Meeting
8
2003
other Articles in the code. Based on this reference to other NEC? Articles, power limited cable used in accordance with Article 725 can be used for low voltage lighting systems, provided that the cable is supplied by a Listed Class 2 or 3 transformer or power supply.
The proper cable would be specified in the installation instructions provided with the Listed system.

The entire document can be found HERE

 

[al hildenbrand]

Re: What makes a Lighting System a System?

Originally posted by ryan_618:
The fire that I observed was started at a free air splice, . . .

Ryan, it almost looks like a "birdseye" or "monkeyface" would have made this compliant. Using the fitting described in 300.16(A) at the surface of the wall, ending the AC or MC (whichever is in the photo) as the sheath is at the exterior surface of the wall, would still have permitted the free air splices.

300.16 Raceway or Cable to Open or Concealed Wiring
(A) Box or Fitting A box or terminal fitting having a separately bushed hole for each conductor shall be used wherever a change is made from conduit, electrical metallic tubing, electrical nonmetallic tubing, nonmetallic-sheathed cable, Type AC cable, Type MC cable, or mineral-insulated, metal-sheathed cable and surface raceway wiring to open wiring or to concealed knob-and-tube wiring. A fitting used for this purpose shall contain no taps or splices and shall not be used at luminaire (fixture) outlets.

It is instructive to me, having just reviewed the products at the Tech Lighting site, to note the changes in the hardware that presents the feed to the open wiring, the "Kable Lite" system.

The photo above shows a round skirt where the cord goes through into the wall.

The new "feed canopy" is rectangular and screws to a standard single gang wall case. The new feed canopy comes pre-assembled with a length of cord and grommet in place in the canopy. See: feed spec sheet. This new system would have the splice inside a box.

 

[pierre]

Re: What makes a Lighting System a System?

411.4((A)(2) Installed using wiring supplied by a listed Class 2 power source and installed in accordance with 725.52 . (for this type of installation, one has to follow Table 11(A) of Chapter 9 ... it is not wholesale permission to use this type of wiring method. Table 11(A) is designed to help reduce the chances of a fire such as Ryan has posted)

The subsection 411.4(A)(1) requires Chapter 3 methods for installations where the wiring method is actually passing through or installed concealed within the wall cavity. It is not required for surface installed wiring methods.

Chapter 4 wiring methods are installed indoors everyday.