Is it legal to have exposed low voltage wiring?

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darekelec

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Hello, gentlemen.
I have a question if it is ok with the NEC to have exposed wiring like speaker, catv, cctv, telephone, data, etc. If yes than to what extend it is legal. what articles cover that?
thank you in advance.
 
darekelec said:
Hello, gentlemen.
I have a question if it is ok with the NEC to have exposed wiring like speaker, catv, cctv, telephone, data, etc. If yes than to what extend it is legal. what articles cover that?
thank you in advance.
Click to expand...

While the question really doesn't have enough information, yes, pretty much all wiring can be exposed although not in all situations, except underground runs and most knob+tube wiring (if not in an attic).

Otherwise each is in its own article: speaker = 640, catv = 820, AFAIK line-level cctv is not referenced, though the power to cameras would usually be in 725, phone and data = 800, etc.

But what do you mean, precisely, by exposed?
 
At what voltage and power level are Chapter 3 wiring methods required?
for example; exposed cables for cctv cameras, coax tv wire stapled to moldings, telephone wire laying on ground.
 
In general, cables can be run exposed for just about anything. For power and lighting circuits, the exposed cable can not be "subject to physical damage" (true also for flex conduits and sch 40 PVC). Subject to physical damage is not well defined in the code, but is up to the inspector to judge. Often times, once the cable is more than 8' above grade/floor, many will allow it exposed.

The CL2/CL3, CATV, Communications, etc cables don't have the physical damage restriction. Note that running speaker or other low voltage cables in the wall will require that you use listed cables (e.g. a CL2/CL3/CM/CATV label on the cable). If you're just running speaker wires from an amplifier, along the floor and up the wall to a ceiling mounted spaeker, I don't think that falls under the NEC and you can use whatever type of cable you want.
 
suemarkp said:
If you're just running speaker wires from an amplifier, along the floor and up the wall to a ceiling mounted spaeker, I don't think that falls under the NEC and you can use whatever type of cable you want.
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Well, for a 1000W amplifier driving a 10 ohm load, you would be looking at 100V and definitely not class 1 or class 2 limited power!
The problem with most generalizations is that they are general.
Maybe not covered by the NEC, but certainly a safety issue even if not covered.

Wires from a 12 volt battery to a 1000 watt inverter have a similar energy problem even though they have a limited voltage.
 
Ok. To make it simpler - I do not work on nuclear plants but on residential apartments mostly. Let me narrow my question to
Is it legal to run exposed cat5 Ethernet cable at baseboard
Same for tv cable
Same for secondary conductors of class 2 power supply
 
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