Low volatage undercabinet lighting

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Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
Wouldn't the CL2 or CL3 cable need to be listed for use as part of a low voltage lighting system?

The section you cited must be from the '08 NEC. since my '05 version does not read like that.
I would think if the wire is rated Class 2 as is the power supply that would be ok.???
 

ike5547

Senior Member
Location
Chico, CA
Occupation
Electrician
I am curious as to 310.10 . What part does this have to do with our application ?

We have 70 C Cl-3 and Cl-2 wire. It is rated for low voltage applications. It's not twisted like speaker Cl rated.
Are we doing something wrong.


A connection at a halogen lamp, for example, might require a higher rating.
 

ike5547

Senior Member
Location
Chico, CA
Occupation
Electrician
Wouldn't the CL2 or CL3 cable need to be listed for use as part of a low voltage lighting system?

411.3 Listing Required.
Lighting systems operating at 30 volts or less shall comply with 411.3(A) or 411.3(B).

(B) Assembly of Listed Parts. A lighting system assembled from the following listed parts shall be permitted:

(6) Cable, conductors in conduit, or other fixed wiring method for the secondary circuit

What I am reading from this is that you need to use listed cable. It doesn't seem to alter the discussion.
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
What I am reading from this is that you need to use listed cable. It doesn't seem to alter the discussion.

segull has a CL-2 wire that is made for them. I don't see any other designation other than CL-2.

We are going to see more and more LED usage for undercabinet ,cabinet lights and such. these lights use hardly any power and a quite cool operating. I have used some ultra-bright LED for a project and the output is far better than FL or Halogen at a fraction of the watts.

I can't see having to use romex to connect to these devices. Ca is on the 05'. In the 05' code all you need is CL-2 from the secondary of a CL-2 trans.
I hope I am not mis interpeting something.
 

ike5547

Senior Member
Location
Chico, CA
Occupation
Electrician
411.3 of the 08' NEC seems to only specify that listed cable be used. CL2 is listed cable.

411.3 Listing Required.

(B) Assembly of Listed Parts. A lighting system assembled from the following listed parts shall be permitted:

(6) Cable, conductors in conduit, or other fixed wiring method for the secondary circuit
 
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macmikeman

Senior Member
This is what I do. I run "listed" smurf tube inside the walls as a chase. I pull the "listed cl2 cables" sold as part of the listed assembly thru that, making sure the smurf is exposed on the ends after the sheetrock is installed. The smurf is not terminated in boxes, so we probably have a code ding right there ,(pretty darn sure smurf is not allowed to not be a complete system), but the inspectors here all love the way I do this. Homeowner has to really peek under to see the 1/4" exposed tube jutting out the wall 1/4" behind the fixture. The other end is hidden above the upper cabinets. 1/2" smurf bends ok in a 2x4 wall, 3/4" smurf will not make the 5 times the od bend rule.
 

mkgrady

Senior Member
Location
Massachusetts
This is what I do. I run "listed" smurf tube inside the walls as a chase. I pull the "listed cl2 cables" sold as part of the listed assembly thru that, making sure the smurf is exposed on the ends after the sheetrock is installed. The smurf is not terminated in boxes, so we probably have a code ding right there ,(pretty darn sure smurf is not allowed to not be a complete system), but the inspectors here all love the way I do this. Homeowner has to really peek under to see the 1/4" exposed tube jutting out the wall 1/4" behind the fixture. The other end is hidden above the upper cabinets. 1/2" smurf bends ok in a 2x4 wall, 3/4" smurf will not make the 5 times the od bend rule.

Let me see if I follow: You run a switched NM to above the cabinet. This pokes out the wall and connects to the primary of trans., each LV light gets a class2 cable run in smurf, the transformer sits on top of the cabinet. How would you do this if the cabinet tops were at the ceiling height?
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
I just looked at a box of Honeywell Genesis Series speaker wire. The work 'speaker' is not printed on the cable or the box's label.


What is printed, minus the obvious or non-relevant stuff, is:

16 AWG 2/C (ETL) 3038058 Type CM/CL2 Sunl. Res. (RoHS) W/O#39984-E2760008


And, printed on the box's label is:

Power Limited Circuit Cable


And, on an added stamp:

Okay to use in accordance with NEC Art. 725 CL2 or CL3 and okay for ETL, CM, CL3
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
According to Article 411 you cannot simply use any cable that is listed. The revision of 411.3(B) was to allow different lighting components made by different manufacturers to be used together to form a system. Previous editions of the code led people to believe that the lighting system needed to be listed as a complete system. The 2008 now gives the option to use listed lighting components from different systems together. I agree that the first sentence is 411.3(B) is poorly worded and does not clear state this intent.
 

ike5547

Senior Member
Location
Chico, CA
Occupation
Electrician
According to Article 411 you cannot simply use any cable that is listed.

I agree.

Using the 08' code now, according to 411.4(A)(2), if the listed cable meets the criteria 725.130(B) then it can used.

For secondary conductors of a class 2 power supply, Larry's listed type CL2 cable meets that minimum criteria as long as it's not installed in a plenum, through multiple floors, and other restrictions on CL2 cables that are spelled out in article 725.
 

macmikeman

Senior Member
Quote:
Originally Posted by macmikeman
This is what I do. I run "listed" smurf tube inside the walls as a chase. I pull the "listed cl2 cables" sold as part of the listed assembly thru that, making sure the smurf is exposed on the ends after the sheetrock is installed. The smurf is not terminated in boxes, so we probably have a code ding right there ,(pretty darn sure smurf is not allowed to not be a complete system), but the inspectors here all love the way I do this. Homeowner has to really peek under to see the 1/4" exposed tube jutting out the wall 1/4" behind the fixture. The other end is hidden above the upper cabinets. 1/2" smurf bends ok in a 2x4 wall, 3/4" smurf will not make the 5 times the od bend rule.

Let me see if I follow: You run a switched NM to above the cabinet. This pokes out the wall and connects to the primary of trans., each LV light gets a class2 cable run in smurf, the transformer sits on top of the cabinet. How would you do this if the cabinet tops were at the ceiling height?

In those cases I put switched nm and the transformer inside the top cabinet , and run the lv cables inside the cabinets in "nice duct", a hinged non metallic raceway sold at ADI.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
I agree.

Using the 08' code now, according to 411.4(A)(2), if the listed cable meets the criteria 725.130(B) then it can used.

For secondary conductors of a class 2 power supply, Larry's listed type CL2 cable meets that minimum criteria as long as it's not installed in a plenum, through multiple floors, and other restrictions on CL2 cables that are spelled out in article 725.


According to the ROC that initiated this change to the 2008 NEC all of the parts used together must be listed as lighting system components. They do not need to be from one manufacturer but they do need to be listed as part of a low voltage lighting system.

Therefore a CL2 cable must be listed as part of a low voltage lighting system in order to use it. Any old listed CL2 or CL3 cable cannot be used.

18-106 Log #2712 NEC-P18
Final Action: Accept

(411.3)
_______________________________________________________________
TCC Action: The Technical Correlating Committee directs that the Panel
reconsider the proposal and add headings to (A) and (B). This action will
be considered by the panel as a public comment.
Submitter:


Steven D. Holmes, Underwriters Laboratories Inc.

Recommendation:


Revise as follows:

411.3 Listing Required. Lighting systems operating at 30 volts or less shall
comply with (a) or (b) : be Listed .
(a) Be a listed lighting system
(b) Be a lighting system assembled from the following listed parts:
(1) Low voltage luminaires
(2) Low voltage luminaire power supply
(3) Class 2 power supply
(4) Low voltage luminaire fittings
(5) Cord (secondary circuit) that the luminaires and power supply are listed
for use with
(6) Cable, conductors in conduit, or other fixed wiring method for the
secondary circuit.
The luminaires, power supply, and luminaire fittings (including the exposed
bare conductors) of an exposed bare conductor lighting system shall be listed
for use as part of the same identified lighting system.
Substantiation:


Problem/Substantiation - Field Assembled Systems - The

wording of Section 411.3 regularly leaves the reader concluding that all parts
of a lighting system operating must be part of one listed entire lighting system.
Lighting systems operating at 30 volts or less have long been field assembled
from individually listed low voltage luminaires, listed luminaire power units,
listed cord, any any involved listed luminaire fittings.
70-453
Report on Proposals A2007


? Copyright, NFPA NFPA 70

Installers verify that individually listed lighting system parts (regularly from
multiple manufacturers) are intended for the use and have the needed ratings,
as indicated in items (a) through (d) below, to create and assemble a low
voltage lighting system. This practice has been successful for many years and
411.3 should make clear that this practice is permitted.
a) The voltage rating of the luminaires and luminaire fittings is confirmed to
match the output circuit voltage marked on the power unit.
b) The total load connected to each power unit output circuit, determined by
adding the wattages of the individual luminaires, is confirmed to not exceed the
maximum permitted total wattage marked on the power unit.
c) For landscape lighting systems, the low voltage circuit flexible cord is
confirmed to be the type and size specified in the power supply installation
instructions for the total connected luminaire load.
d) For other than landscape lighting systems, the low voltage circuit
conductors are confirmed to have an ampacity suitable for the total connected
load.
Proposed 411.3 provides for both (a) the situation where an entire listing
system is packaged and listed as a complete lighting system and (b) the
situation where individually listed lighting systems parts are field assembled
into a lighting system.
The ability of assembled exposed bare conductor lighting system parts to
comply with the performance and other requirements in the Standard for Low
Voltage Lighting Systems, UL 2108, always depends on only parts of the same
identified lighting system being used together. The last sentence of proposed
411.3 addresses this.
Panel Meeting Action: Accept
Panel Statement:


The panel accepts the submitter?s concerns and urges the

standards and certification agencies to consider it important that the power
supply installation instructions specify the type of conductor, size, and length.
Number Eligible to Vote: 13
Ballot Results:


Affirmative: 13
______________________________________________

 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
I think you are reading more in to that than was intended.

Actually I think that it's really the opposite. The intent was that all components be listed (togehter or individiually) as part of a low voltage lighting system. The wording of that code sections fails to properly convey the requirement.
 

ike5547

Senior Member
Location
Chico, CA
Occupation
Electrician
The way I see it, the cable described in post #30, if installed for low voltage lighting, becomes a 'listed part of a low voltage lighting system" by default.

I believe what prompted the code change in 411 had more to do with mixing and matching different transformers, fixtures, etc., and that the new wording did not add additional restrictions on cables that were not already there in the first place.

The new wording in the 08' code bares this interpretation out.

411.3 Listing Required.

(b) Be a lighting system assembled from the following listed parts:

(6) Cable, conductors in conduit, or other fixed wiring method for the
secondary circuit.


Note the bolding in (6). The cable is to be listed for the "secondary circuit" not the low voltage lighting per se.
 

mtnelectrical

Senior Member
Finally he red tagged my low voltage installation. Inspector came yesterday to inspect, I wasn't there I had a fire emergency in another town but sent my mechanic to pass the inspetion. We used this wire E1052S
http://www.generalcable.com/NR/rdon...F88D2FDC2A/0/Pg110_MultiCondUnShieldRiser.pdf
of course the 72'' wires that come with the under cabinet lights don't rech the tranx so we have to extend the wires, and because of the kitchen layout we had to run it inside the wall for 24'', now inspector want us to remove all this wire and install MC cable from every light to the tranx. he said this low voltage cable needs protection from physical damage,(maybe the can of salt would corrode the wires)
My question is, Is low voltage system considered power limited controlled circuit? If it is, we could use any listed wire for such circuit, I am just talking about the secondary circuit wiring.
and this wiring does not need protection from physical damge, even the splices are allowed outside a box.
 
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BMacky

Senior Member
Location
Foster City, CA
I've heard about, and used Tray Cable (TC) and it seems to be popular around here (San Fran Bay Area) for low voltage applications. Supply houses seem to be selling enough of it to people asking the same question.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
MC cable, this guy sounds a little nuts. But the subject physical damage application is discretionary since not everyone sees it the same way. My under cabinet lighting, wired with NM cable has never even been touched in the 10 years that it's been installed so IMO it will never be damaged if installed properly.
 
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