Question about In wall speaker wire / Oxygen free wire (1 Viewer)

[Jim Tressler]

This is from parts express, part #100-740. I am thinking about this wire.. anyone have any opinions? Its rated in wall - my local building code does not require the CL3R rating for in wall.. so i am thinking about the sound king 12 gauge, what would you recomend?

What does that mean? More marketing?

"12 gauge wire consists of 19 x .0185 gauge strands of ASTM B-3, B-8, and B-286 copper"

Finally does "oxygen free" make a difference?

thanks!

Jim

 

[Bill Kane]

Jim, this Carol in-wall wire is good for attic and wall runs, as specified. I just got a 100-foot piece. The sheath seems to be PVC but it is not very substantial in the hand. Still, it's code-rated and quite flexible.

The CL3 rating I believe relates to "plenum" use, those open shafts in multistory buildings, so that any flames there dont cause the wire sheath to emit toxic fumes that cud be carried throughout the structure. Typical bldg code still requires CL2 rating for attic/wall type installation, and I believe this Carol also fits that bill.

Because your code doesnt require CL3 doesnt mean you can run regular SoundKing 12ga with ordinary sheathing.

bill

 

[Jim Tressler]

thanks bill.. i am assuming it is easy to work with and sounds as "good" as other wire?

 

[Bill Kane]

well, I am of the wire-is-wire school and if the application is for rear surrounds, where the conventional advice is to use 12ga for runs 25 feet-plus, then I think this is the wire you'd want.

It does look "industrial" but who cares if the final 3-5 feet out of the wall to the amplifier is behind the rack/gear set up.

 

[Chu Gai]

ASTM: American Society for Testing Material

B-3: specifies bare soft, annealed copper (refers I think to a single strand)

B-8: concentrically compressed strands (refers I think to strands)

B-286: refers to the lay length which is defined as the distance required to complete one revolution of the strand around the diameter of the conductor. For most conductor applications, lay lengths of between 8 - 16 times the outer diameter of a particular layer are specified by ASTM B 286.

OFC is a generic term meaning oxygen free. It can be produced in a variety of grades depending upon the end use of the application (gaskets, vacuum devices, superconductivity, etc.) but it is typically associated with having a low oxygen content, low impurities, and what is known as no hydrogen embrittlement. I don't recall the minimum amount of oxygen allowed.

The copper itself is available in various levels of purities which would still meet the above standards (99.95%, 99.999%). Various wire companies will attempt to gain some marketing hype with this and charge accordingly.

Class 2 & 3 circuits have to do with that portion of the wiring that is between the load side of the power source and the connected equipment. It is concerned with safety from a fire initiation standpoint. Class 3 deals with greater voltages and currents than Class 2. Accordingly one then has additional safeguards to provide protection from any electric shock. Consider Class 3 to be more rigorous than Class 2. They can be run through a plenum or ductwork but its not necessary. To meet code, when they're run through walls or ceilings in an exposed manner, they're supposed to be attached to the structural components (joists, studs, etc) at intervals not exceeding 5 feet. Straps, staples, hangers, etc. are used.

Your local building inspector, if you can get the person can further elaborate.

 

[Lee Scoggins]

Finally does "oxygen free" make a difference?

Yes. In my experience it does.
Lee

 

[Chu Gai]

almost tough these days not to find OFC especially in audio applications