Can audio cables be buried without conduit?

[cppoly]

Looking for this requirement and having a hard time finding it.

I checked article 640 for audio equipment and it bounces you back to article 725. Can't find it in here either. Any ideas?

 

[tthh]

640.9

 

[hbiss]

Can audio cables be buried without conduit. Well, nothing says you can't, nothing different than landscape lighting wiring. I'm assuming outdoor speakers?

-Hal

 

[don_resqcapt19]

640.9(C) sends you to Article 725, so look at 725.3(L).

 

[hbiss]

We haven't established whether this is CL2 or something else. That's why I asked if this was for speakers.

Regardless of what it is however, you do want to use cable suitable for direct burial which is what 725.3(L) is telling you.

-Hal

 

[cppoly]

Thanks, yes it is for speakers.

For minimum burial depth, 725.3(L) says to comply 300.5(B). Since speakers are 70V (class 2) and wiring won't be installed in conduit, looks like 300.5(B) is requiring minimum burial depth of 24 inches if installed under dirt??

 

[retirede]

Old PA systems with transformers at each speaker were 70.7 V wiring. I don’t believe low impedance speaker wiring is considered 70V, unless there is come code definition that I’m not aware of (very possible).

 

[don_resqcapt19]

Thanks, yes it is for speakers.

For minimum burial depth, 725.3(L) says to comply 300.5(B). Since speakers are 70V (class 2) and wiring won't be installed in conduit, looks like 300.5(B) is requiring minimum burial depth of 24 inches if installed under dirt??

No burial depth is specified in the code for that application as 300.5(A) is not referenced in Article 725 and the parent text of 725.3 says only the sections of Article 300 that are referenced within Article 725 apply to an Article 725 installation. 300.5(B) only tells you that interior of underground raceways is a wet location, but has nothing to do with the burial depth of the raceway or cables.

 

[hbiss]

Old PA systems with transformers at each speaker were 70.7 V wiring. I don’t believe low impedance speaker wiring is considered 70V, unless there is come code definition that I’m not aware of (very possible).

An old amp with a 70.7 volt output and not having any marking to indicate that CL2 wiring may be used must be wired as Class 1 with a Chapter 3 wiring method.

Most amps of recent vintage, even with a 70.7 or 100 volt output will be marked and listed for a CL2 wiring method.

-Hal

 

[LarryFine]

The output voltage of my amplifiers is around 50 volts.