Speaker wire rated for "in wall" use

[erock33]

Ok, my basement is finished, speaker wire already ran and behind drywall. Im 90% sure it is not CL rated for in -wall use (clear sheathing and I can see the copper wires). But my real confusion is about the need for "rated" in wall speaker wire in the first place. IF, the speaker wire itself is not going to cause a fire (does speaker wire get hot enough to do that?), but the reason for CL rated wire is because it does not give off deadly fumes, what does it matter? In other words, if you do not put your speaker wires inside your wall but on the outside, somehow they will not give off these fumes, and its ok to use non-CL rated wire?. If your house is burning, as in burning down, the speaker wire is going to get burned whether its in the wall of not. Seems like some bueracratic(sp) nonsense to me. This is my way of trying to justify not modifying my setup, too many long runs to even know how to begin changing it. What say you?

 

[highfigh]

Ok, my basement is finished, speaker wire already ran and behind drywall. Im 90% sure it is not CL rated for in -wall use (clear sheathing and I can see the copper wires). But my real confusion is about the need for "rated" in wall speaker wire in the first place. IF, the speaker wire itself is not going to cause a fire (does speaker wire get hot enough to do that?), but the reason for CL rated wire is because it does not give off deadly fumes, what does it matter? In other words, if you do not put your speaker wires inside your wall but on the outside, somehow they will not give off these fumes, and its ok to use non-CL rated wire?. If your house is burning, as in burning down, the speaker wire is going to get burned whether its in the wall of not. Seems like some bueracratic(sp) nonsense to me. This is my way of trying to justify not modifying my setup, too many long runs to even know how to begin changing it. What say you?

The deadly fumes issue is for plenum-rated cabling, not in-wall. Class 2 is explained in this link- it's for flame/spark propagation and voltage insulation rating, not fumes. Non-CL-2 wire has been used before and it hasn't been a problem because it was a case where nothing went wrong enough to make it a problem. Remember- the signal from amplifiers isn't the only thing that can pass through the wire in a worst-case situation.

http://www.electriciansparadise.com/neccabling.html

 

[MDS]

Regardless of the perceived non-risk of not using CL rated wire in-wall, if you were ever so unfortunate to actually suffer a house fire your insurance company will deny any and all claims because your wiring wasn't up to code requirements.

That alone should be reason enough to do it right.

 

[highfigh]

Regardless of the perceived non-risk of not using CL rated wire in-wall, if you were ever so unfortunate to actually suffer a house fire your insurance company will deny any and all claims because your wiring wasn't up to code requirements.

That alone should be reason enough to do it right.

Obviously, this would only be denied if the wiring is the cause but that is definitely a major concern. Unfortunately, it's also still a problem because many DIYers and some installers don't seem to care enough to know what is required, so they still use zip cord. If landscape lighting wire wasn't so cheap, people wouldn't use it.

 

[Nugu]

It's also a issue of spreading (not causing) a fire. A lot of times doors and walls are required to take X time for a fire to penetrate. (You'll see that on attached garage doors a lot) Cabling not rated for in wall use can act like a wick negating that type of defense.


Here's a easy experiment, take a piece (1-2 ft) of the wire you used and try lighting it on fire at one end with a lighter. If it burns like a lot of plastics will then imagine that going up through your walls.

 

[Alex2507]

CL-2 sounds better.

 

[Rickster71]

... Seems like some bueracratic(sp) nonsense to me...

All great posts / replies in this thread, and I couldn't agree more.(with all)

With that being said. You are on to something, the NEC is a bit of
The Tail Wagging the Dog. All of our national codes are insurance company driven.

 

[highfigh]

All great posts / replies in this thread, and I couldn't agree more.(with all)

With that being said. You are on to something, the NEC is a bit of
The Tail Wagging the Dog. All of our national codes are insurance company driven.

That may be but the goal of the NEC is to keep people alive and that's not a bad thing (arguable, since the quality of the person isn't subject to their goal).

 

[Rickster71]

That may be but the goal of the NEC is to keep people alive and that's not a bad thing (arguable, since the quality of the person isn't subject to their goal).

The part of The Code that always got to me was:

"The purpose of this Code is the practical safeguarding of persons and property."....

"...to result in an installation that is free from hazard, and not necessarily efficient, convenient, or adequate for good service or future expansion."

 

[erock33]

Nuju gave us the idea and I put it to test. In order of full disclosure here when I started this thread I used Megacable flatwire from radioshack in my walls, WHY? is a great question. The reason is I had a boatload of it so it was free 14GA wire. Not the best idea, I agree, but its there now. Anyway, I am not sure that it is rated CL or for inwall use or not. My guess is that it is not because the sheathing is clear and I can see the copper wires inside the sheath.

I took a foot length of my megacable flatwire and a rated in wall wire and put a flame to both. After it appeared there was a good flame taken hold on the wire I removed the external flame. BOTH pieces of speaker wire could not hold the flame for longer than 3-4 seconds and both flames went out on there own. (actually, after multiple attempts to ignite it, it wouldn't hold the flame longer than 2 sec)

I feel alot better about my situation having done this. Try it for yourself, if you have any doubts.

 

[highfigh]

The part of The Code that always got to me was:

"The purpose of this Code is the practical safeguarding of persons and property."....

"...to result in an installation that is free from hazard, and not necessarily efficient, convenient, or adequate for good service or future expansion."

Why don't they just come out and say it?- "The purpose of this Code is the practical safeguarding of persons and property so the insurance companies don't need to pay when a fire is caused by inadequate wiring"

Good design within the boundaries of the code takes care of how well it works and how easy it is to expand. I would hate to be the guy who gets a call saying that someone died because of me taking a shortcut to save money by not using plenum rated cable in a cold air return. The option is to run it in conduit where air could be drawn from and seal any openings. My option was to buy a roll of PL rated conduit and Cat5e for less than 10' of cold air return and my cost would have been over $500 plus travel time to the distributor. That would leave me with 95% of both spools and I'd bet that I wouldn't need it until it's completely unnecessary.

 

[highfigh]

Nuju gave us the idea and I put it to test. In order of full disclosure here when I started this thread I used Megacable flatwire from radioshack in my walls, WHY? is a great question. The reason is I had a boatload of it so it was free 14GA wire. Not the best idea, I agree, but its there now. Anyway, I am not sure that it is rated CL or for inwall use or not. My guess is that it is not because the sheathing is clear and I can see the copper wires inside the sheath.

I took a foot length of my megacable flatwire and a rated in wall wire and put a flame to both. After it appeared there was a good flame taken hold on the wire I removed the external flame. BOTH pieces of speaker wire could not hold the flame for longer than 3-4 seconds and both flames went out on there own. (actually, after multiple attempts to ignite it, it wouldn't hold the flame longer than 2 sec)

I feel alot better about my situation having done this. Try it for yourself, if you have any doubts.

That's open flame but if lightning decides to go on tour of your house's wiring, it's amazing how fast a short circuit burns insulation. I shorted a wire connected to the hot terminal of the fuse block to the frame of the dash when I was working on a car stereo a long time ago and about 1' of the insulation burned away in a fraction of a second. I never expected it to go so fast but when the available current is high and the path to ground is short, it gets hot really fast. It's really not about open flame- it's "What if?" in the extreme sense. I would look on the Radio Shack site for specs.

As an aside, I helped a former employer with some install work a few years ago and when I went into the basement of the house to fish some cables, I looked up and saw the wiring done by a previous dealer. Zip cord and a wire-wound ceramic resistor used to drop the level of a speaker with bare solder joints at both ends of the resistor. That wouldn't have been so bad if the resistor hadn't gotten so hot that it charred a 6" circle in the floor joist because it had nothing behind it to insulate the wood.

 

[Nugu]

I didn't even realize it till I stumbled over it but AH actually has a write up that covers this.

http://www.audioholics.com/education/cables/understanding-in-wall-speaker-video-and-audio-cable-ratings

Something you may want to look into on the manufacturers site

So, if a cable isn't marked CL2 or CL3, is it suitable for in-wall installation? It may be. The NEC allows cable of a higher rating to be substituted for a lower rating, and therefore, any of the following may be used: CM, CMP, CMR, CMG, CL2R, CL3R, CL2P, CL3P, PLTC. CMX also may be used where CL2X or CL3X is required.

It's not a uncommon practice to sell 2 products that are the same thing minus the labeling stating it meets X requirement because it's cheaper to mass produce 1 thing instead of 2 slightly different things.


But again, every reason for the use of rated cable has been stated in this thread. It's your choice to live with not ours. Also realize you can usually just pull-through a cable to replace the old ones - you don't have to rip out dry wall always.