On September 20, 2009 at 20:35, theKevin said...
you know, as funny as this thread is, and as one poster even asked for a refund after reading it, i gotta say:
i have been doing this for almost a decade and i admit i never thought about the fact that 100W into 8Ohms means 28.28V, and that if you have a 140W amp powering 8Ohm speakers, you need CL3 rated speaker wire to be code compliant. Honestly, how many people here make that distinction between amps of different power?
On September 20, 2009 at 20:43, theKevin said...
i realize my experience is relatively limed, especially compared to many posters here, but how many of you have ever seen or heard of an inspector checking the impedance and power of a low voltage installation? i'm sure it's happened, but in the real world i don't think it happens 1% of the time, at least in the world of residential av.
They would not measure the installed components. The cabling is passed/failed before the systems are connected.
The differentiation is the
type of systems which the cabling is intended to be used with.
Something that is KNOWN to be low-powered (like intercoms, burglar alarm sensors, or a doorbell chime) would classify as Class 2 and require cabling marked as CL-2 (or CL-3)...
Something like whole-house audio or an HT receiver is generally regarded as a Class 3 (regardless of whether it's above or slightly below the threshold) and require cabling marked as CL-3.
39,
Here is more clarification from Article 725 of the NEC Handbook for you to chew on...
This is in the context of interconnectivity between freestanding computer components, but you could draw the parallel to freestanding audio/video components.
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If the listed computer components are interconnected and all of the interconnected equipment is in close proximity,
the wiring is considered an integral part of the equipment and therefore not subject to the requirements of Article 725.
If the wiring leaves the group of equipment to connect to other devices in the same room or elsewhere in the building,
the wiring is considered "wiring within buildings" and is subject to the requirements of Article 725.
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So, you can use your "parallel wire" as speaker wire within a rack or stack of electronics, but not throughout the house.
