70 Volt Speaker Wiring

[PapaGreg]

What are the approved wiring methods for 70.7 volt speaker systems? I looked in Articles 720 and 725 but not sure how they apply.

 

[hbiss]

You might also want to look at 640.8(C). Basically you follow the same rules as any power supply. The required wiring method will be marked on the rear of the amp near the output. Class 2, Class 3 or Class 1. Class 1 requires a Chapter 3 wiring method, CL2 and 3 can be any cable with that listing run exposed.

-Hal

 

[GoldDigger]

You might also want to look at 640.8(C). Basically you follow the same rules as any power supply. The required wiring method will be marked on the rear of the amp near the output. Class 2, Class 3 or Class 1. Class 1 requires a Chapter 3 wiring method, CL2 and 3 can be any cable with that listing run exposed.

-Hal

Or Class 2 or 3 wiring specifically rated for concealed use. And/or plenum rated if in a ceiling space used for environmental air.

 

[hbiss]

I think all CL2 and CL3 listed cable is listed for concealed use. By "exposed" I meant no raceway or conduit required. Of course if you are running it within an environmental air handling space such as above a dropped ceiling used for HVAC return air, you would use a plenum listed cable-CL2P or CL3P. For Class 1, Chapter 3 will dictate what to run in an air handling space. No different than power and light.

-Hal

 

[newbinga]

Just got my LV license so learning, so dont mind the repeated question and I am having a hard time understanding what is meant in this thread.

The amp we are looking at is class 2 and the runs will be in a retail store with open ceilings. the speakers will be mounted to the beams.

Are we saying that all class 2 wiring is classified as concealed, and that if it is running in an open ceiling it needs to be in conduit?

Guess I better pull my code book out...:slaphead:

 

[GoldDigger]

Just got my LV license so learning, so dont mind the repeated question and I am having a hard time understanding what is meant in this thread.

The amp we are looking at is class 2 and the runs will be in a retail store with open ceilings. the speakers will be mounted to the beams.

Are we saying that all class 2 wiring is classified as concealed, and that if it is running in an open ceiling it needs to be in conduit?

Guess I better pull my code book out...:slaphead:

No, the statement was that essentially all wiring that is rated for Class 2 is rated for concealed use. Unconcealed use is also allowed, not necessarily even protected from damage.
If the wiring is not concealed, there may be a few other wire types (CMX, PLTC) that you can use as well as CL2.

 

[gadfly56]

Fire Alarm?

Fire Alarm?

Are these speaker for use in a fire alarm voice evacuation/mass notification system?

 

[hbiss]

I think the question came about because you will undoubtedly find in the course of your LV work, wiring like lamp cord (zip cord), SO cord, extension cords and all kinds of junk from China. None are CL2, CL3, or CM listed on the jacket yet you will find it run within walls and ceilings and through holes in walls to the other side. That's what's meant by concealed.

If you want to run wiring within walls it must be a CL or CM listed wire or cable. This is not to say that a CL or CM wire or cable can't be run exposed also.

-Hal