Speaker Wire In walls Residential

[lightspeed]

What is a CL rating on speaker wire, Ihad an inspector in Brookline Mass. who said speaker wiring in a ceiling or wall has to have a CL rating, refering to its insulation I guess, I looked under ART. 645 and 725 and couldn't find any info. Also does the code allow low voltage and line voltage in the same wall cavity but on opposite studs or do you have to run the LV wire in another cavity altogether, my buddy is a union electrician and he says that that is code. Lightspeed

 

[jrdsg]

CL rating

CL rating

The only CL marking required on an in-wall speaker cable would be NEC CL2 or class 2.

Canada has another CL marking [CL-XXXX] where the "CL" refers to "coil lead" wire and the X's refer to the temp rating of the insulation jacket [For a non-speaker wire example, CL-1254 is 600V, 125 degrees C.] But this is unrelated to your speaker wiring issue.

Canada would also require a minimum FT4 [riser] rating for in-wall use.

Speaker wire is prone to pick up interference from parallel runs of power wiring, but it is not necessary to run them in separate wall cavities, just to physically separate and secure them.

Arguably parallel runs on opposite sides of the same wood stud, in different cavities, would be closer together [1.5" apart] than parallel runs on adjacent studs [14" apart].

Of course I could be totally out to lunch here...

 

[hbiss]

If you looked at Art 725 and didn't see that you better get glasses. Low voltage wiring for concealed installations needs to be either CL2 or CL3 listed. It will be printed on the jacket.

There is nothing in the Code about separation.

-Hal

 

[Speedskater]

I think that you could also use any of the following:

CMP, CL3P, CL2P, CMR, CL3R, CL2R, CM, CMG, CL3, CL2, CMX, CL3X

But you are much more likely to find CL2 at a good price.

 

[hbiss]

If you read Art 725 you'll see that the "P" suffix stands for plenum, the "R" for riser and "X" is limited use. CM is communications multipurpose, generally something like CAT3 or 5 or coax and many will have a dual listing as CL2 or 3. These are all listed cables and can be used withing a structure.

Again, read 725 and 800 for the full explanation.

-Hal

 

[lightspeed]

speaker wire

speaker wire

Thanks for responding Hal, I looked online and i seen on there that in ressy work you have to at least have a class 2 rating, but I ma still trying to determine the different classes for low voltage, can you clarify a little or bring a little insight on the suibject. lightspeed

 

[tom baker]

Lightspeed: There is an entire article on speaker wiring. See NEC Article 640. Reviewing that would be a good start.

 

[hbiss]

Forget about residential work vs commercial work, it's all the same. We have talked about LV wiring many times here before. The wiring method you use is dictated by the listing of the power supply. If the label on a transformer says class 2 or CL2 then you would use a CL2 or a CL3 wiring method. That would include using one of the cables permissable in Art 725 for CL2 or CL3 wiring as well as being listed for the environment where the wiring will be installed.

That said, consumer audio equipment won't have a listing for it's speaker outputs because it was not meant to be permanently installed. There is also a lot of other equipment that requires signal level premises wiring that won't have such a listing. Think data, telephone and CATV wiring.

For this you may use any wire you think is suitable as long as it is listed for permanent installation within a structure and the environment. Art. 725 on up contains that information.

-Hal