low voltage zip cord in residental walls

[bassphisher]

I am seeing contractors use a lot of #12 stranded underground LV zip type cable in walls.For LV puck type lighting.I don't believe that you can install this type of cabling concealed inside walls because of the insulation.The contractors like it because it is stranded and easy to terminate.
Does anyone know of a code compliant substitute?

 

[hbiss]

Re: low voltage zip cord in residental walls

Beaten this subject to death. Any class 1 wiring method can be used. NM (Romex) is the most practical.

-Hal

 

[tom baker]

Re: low voltage zip cord in residental walls

Not quite dead yet. The 2005 NEC adds an exception for Art 411 lighting to use class II wiring if its 100 VA or less. See 411.4 (A)(2).
But this still does not allow zip cord

 

[petersonra]

Re: low voltage zip cord in residental walls

Originally posted by tom baker:
Not quite dead yet. The 2005 NEC adds an exception for Art 411 lighting to use class II wiring if its 100 VA or less. See 411.4 (A)(2).
But this still does not allow zip cord

is there some inherent danger in using zip cord for this type of application? It does not seem so.

 

[bassphisher]

Re: low voltage zip cord in residental walls

http://www.electrical-supply.net/category.asp_Q_parentid_E_105_A_subcatid_E_110
Here is a web site that sells the cable that I am talking about.I included this because I want to make sure that we are all talking about the same thing.
One of my concerns are the smoke characteristic of the insulation.Some of the cable ends up being exposed (usually above a cabinet or some out of the way place).

 

[hbiss]

Re: low voltage zip cord in residental walls

is there some inherent danger in using zip cord for this type of application? It does not seem so.

Unless the cord is marked CL2 you can't use it. I'm not going to try to guess why lamp cord can't be used for fixed wiring any more than I would any other flexible cord.

bassphisher, we all know what you are talking about. That is landscape wiring suitable for direct burial. Probably not even listed for use within a structure if you were to locate tha LV transformer there.

-Hal

[ September 09, 2005, 12:57 PM: Message edited by: hbiss ]

 

[petersonra]

Re: low voltage zip cord in residental walls

Originally posted by hbiss:
is there some inherent danger in using zip cord for this type of application? It does not seem so.
-Hal

I am not arguing whther it is allowed, but whether there is some inherent hazrad if one were to use it. I just can't come up with a valid reason it would be inherently hazardous.

 

[luke warmwater]

Re: low voltage zip cord in residental walls

For starters. Amps are Amps.
It would really depend on the load.

For example, we have a kitchen right now with 'low-voltage' under-cabinet lights. There are (17) double 5-watt xenon heads. That's 170watts @ 12volts. Which equals 14.16amps.

Then there are the above cabinet lights. Another 170watts @ 12volts. Now we are over 28amps.

We do everything overkill anyway, so we have (2) circuts for the cab.lts.

If there are several sets of wires running to idividual or small numbers of lights, then I guess each whip would have less current on each.

But, if the puck lights are jumped from light to light to light etc, the full current would be running on the wire, no?

 

[hbiss]

Re: low voltage zip cord in residental walls

I just can't come up with a valid reason it would be inherently hazardous.

Okay, I'll take a stab at it and guess that the insulation material is designed around the requirements of a flexible portable cord that is supposed to be inspected for damage at regular intervals.

The insulation on many of these cords can be easily damaged and some can become brittle over time. Obviously if it is buried in a wall you aren't going to see any of that.

-Hal

 

[pierre]

Re: low voltage zip cord in residental walls

This is a topic that seems to come up a lot at work. Art 411 requires a chapter 3 wiring method of which SPT and landscape lighting cable is not.
As far as the danger, I believe that the insulation does not meet the "smoke" requirements.

 

[iwire]

Re: low voltage zip cord in residental walls

Pierre there is a change to this for 2005.

 

[pierre]

Re: low voltage zip cord in residental walls

Good morning Bob
I am aware of the 05 change, I did not address it, as I think most jurisdiction have not yet changed to the 05 NEC.
Since you have (and Tom Baker also has) brought this up, I would like to point out that this change has a caveat - read Mark Ode's article in the IAEI or UL's Code Corner to see how restrictive this change can be.

This change, and Mark's article also show how important it is to be aware of other facets of our industry in order to make a correct installation - another great reason to keep in tune with the forums!!!

 

[hbiss]

Re: low voltage zip cord in residental walls

I believe that the insulation does not meet the "smoke" requirements.

That would go without saying and is the purpose of listing a cable for riser, plenum or general purpose use. None of the flexible cords are subject to being listed this way because they are not intended to be used in place of permanent wiring. Your landscape wire is not intended to be used within a structure so it's not listed this way either.

-Hal

-Hal

 

[tom baker]

Re: low voltage zip cord in residental walls

The danger with the zip cord is that it does not meet the vertical flame resistance test. IE If it starts burning the flame will travel vertically up the cable. CL2 cable meets the flame test.
Also zip cord and SO type cord will have the insulation dry out and crack over a long time, perhaps 15 years. if its in the wall you can't see it. This is why those products can not be in a ceiling space

 

[sparky_magoo]

Re: low voltage zip cord in residental walls

I was following this thread. In the 2005 code, I read 411.4 (A) 1. I don't know what chapter 3 the book is referring to. Please help. I will be installing four 23 foot rope lights along on the top of four exposed beams in a great room next week. I was instructed to run a 10 AWG zip cord to each rope. I have concerns about fishing the four zip cords through the wall to the j-box housing the x-frmr. Any thoughts form the brain trust?

 

[iwire]

Re: low voltage zip cord in residental walls

As these guys have been saying zip cord is not acceptable in walls.

When the NEC says use a "Chapter 3 wiring method" that means you get to choose any method from Article 300 through 398 that is proper for the area you are working.

For what your doing NM (Article 334) will likely be you choice.

 

[pierre]

Re: low voltage zip cord in residental walls

Running cords through walls is not permitted. Take a look at number 2.


Art 400 Flexibe Cords and Cables

400.8 Uses Not Permitted. Unless specifically permitted in 400.7, flexible cords and cables shall not be used for the
following:
(1) As a substitute for the fixed wiring of a structure
(2) Where run through holes in walls, structural ceilings,
suspended ceilings, dropped ceilings, or floors
(3) Where run through doorways, windows, or similar openings
(4) Where attached to building surfaces
Exception: Flexible cord and cable shall be permitted to be attached to building surfaces in accordance with the provisions of 368.8.
(5) Where concealed by walls, floors, or ceilings or located above suspended or dropped ceilings
(6) Where installed in raceways, except as otherwise permitted in this Code

 

[bassphisher]

Re: low voltage zip cord in residental walls

Ok is seems that we have established that you can not use this type of cable concealed in walls.
So here is the next problem.This installer wants to install a 2 gang box in the wall(with a divider)for the 60w xfmr.So now we know that out of this box he has to use a wiring method in chapter 3.We are talking about a residential installation so nm cable would be his choice.These lights come from the factory with only 6 inches more or less of 2 individual high temperature wires coming out of them.And the lights are designed to be cut directly into the top of a cabnet.So heres the next problem in this area we don't allow exposed romex,they want to poke the romex out of the wall and make exposed joints onto the short factory wires.Even if they install a box in the wall directly behind each light they still have to extend the factory wires to reach the box in the wall.
Any suggestions,
Paul

[ September 12, 2005, 10:28 AM: Message edited by: bassphisher ]

 

[pierre]

Re: low voltage zip cord in residental walls

Paul
They may not permit the use of NM Cable exposed that carries line voltage. Find out if it is permissible to use NM Cable that carries 12 volts.

 

[hbiss]

Re: low voltage zip cord in residental walls

Another thing that may be less obvious is that even though these lights are sold doesn't mean they can be used. Are they listed? Most manufacturers of this stuff seem to be oblivious to the code requirements for their wiring and installation. It would be easy to make accommodations for the allowed wiring method if they did their homework.

That's why many of us including myself stay away from this stuff.

-Hal