# High and low voltage in same conduit



## AMPED

I have an existing 1 inch conduit that is ran underground. Can I run speaker wires and a 3 # 12 wires for a 120 VAC 20 amp circuit in the same conduit? and if I can what type of speaker wire should I install.

Thanks


----------



## running dummy

What you need to be worried about here is the voltage rating of all wire insulation involved. Don't know if you can find legit speaker wire around here with the higher rating. 

As a design stand point I also don't think it's a good idea. I would imagine there would be a lot of noise/distortion imposed on the speaker system.


----------



## wildleg

no, except under very specific circumstances (I am assuming the speakers are powered by a class 2 power source). read 725 starting here:

725.136 Separation from Electric Light, Power, Class 1,
Non–Power-Limited Fire Alarm Circuit Conductors, and Medium-Power Network-Powered Broadband 
Communi- cations Cables.

(A) General. Cables and conductors of Class 2 and Class 3 circuits shall not be placed in any 
cable, cable tray, com- partment, enclosure, manhole, outlet box, device box, race- way, or similar 
fitting with conductors of electric light, power, Class 1, non–power-limited fire alarm circuits, 
and medium-power network-powered broadband communica-
tions circuits unless permitted by 725.136(B) through (I).


----------



## AMPED

My initial responce to the customer wanting the bid was no I cannot do it. Then I was informed that the two competing electrical companies assured him it could be done. They would just have to install a speaker wire with a heavier insulation.


----------



## westcojack

It is a very bad idea to do this, and probably not per code. Bad idea, as there will be a tremendous amount of noise on the speakers. I wouldn't do it and explain why in my bid. If the home owner cares about the install and not just the $$$, we will not use the other contractors.

If you look at the exceptions to 725.54 if they control wires and are associated with the high voltage (120v) devices and controls, you are able to as long as the rating on the low voltage cable jacket meets the conditions below, you can.

725-54 Does does not address speaker wires.





725-54. Installation of Conductors and Equipment
(a) Separation from Electric Light, Power, Class 1, Nonpower-Limited Fire Alarm Circuit Conductors, and Medium Power Network-Powered Broadband Communications Cables.
(1) In Cables, Compartments, Cable Trays, Enclosures, Manholes, Outlet Boxes, Device Boxes, and Raceways. Cables and conductors of Class 2 and Class 3 circuits shall not be placed in any cable, cable tray, compartment, enclosure, manhole, outlet box, device box, raceway, or similar fitting with conductors of electric light, power, Class 1, nonpower-limited fire alarm circuits, and medium power network-powered broadband communications cables.
Exception No. 1: Where the conductors of the electric light, power, Class 1, nonpower-limited fire alarm, and medium power network-powered broadband communications circuits are separated by a barrier from the Class 2 and Class 3 circuits. In enclosures, Class 2 or Class 3 circuits shall be permitted to be installed in a raceway within the enclosure to separate them from Class 1, electric light, power, nonpower-limited fire alarm, and medium power network-powered broadband communications circuits.
Exception No. 2: Conductors in compartments, enclosures, device boxes, outlet boxes, or similar fittings, where electric light, power, Class 1, nonpower-limited fire alarm, and medium power network-powered broadband communications circuit conductors are introduced solely to connect to the equipment connected to Class 2 or Class 3 circuits to which the other conductors are connected, and
a. The electric light, power, Class 1, nonpower-limited fire alarm, and medium power network-powered broadband communications circuit conductors are routed to maintain a minimum of 0.25 in. (6.35 mm) separation from the conductors and cables of Class 2 and Class 3 circuits, or
b. The circuit conductors operate at 150 volts or less to ground and also comply with one of the following:
1. The Class 2 and Class 3 circuits are installed using Type CL3, CL3R, or CL3P or permitted substitute cables, provided these Class 3 cable conductors extending beyond the jacket are separated by a minimum of 0.25 in. (6.35 mm) or by a nonconductive sleeve or nonconductive barrier from all other conductors,


----------



## uconduit

Can someone please explain why they believe that speaker wire has to say the words "speaker wire" on it?


----------



## wildleg

uconduit said:


> Can someone please explain why they believe that speaker wire has to say the words "speaker wire" on it?


who is they ?


----------



## uconduit

wildleg said:


> who is they ?


Whom ever


----------



## Dennis Alwon

Speaker wire is generally a class II wiring but I think the insulation is rated 300V. Would I do it-- no ...Is it legal -- perhaps. The question is if the speakers are from a class II source.


----------



## hardworkingstiff

Can you do it, yes. Will it work OK, possibly (shielded cable grounded at one end might keep the AC noise out of the speaker).

Will it be code compliant? Doubtful. As others have said, most of the time speakers are not supplied by a Class 1 power supply. Conductors from Class 2 & 3 power supplies are not allowed to be installed in a conduit with power conductors.

I have done it before and gotten away with it. I don't do it know.


----------



## manchestersparky

According to 725.130(A) exception No. 2- you could reclassify the class 2 circuit to a class 1 circuit. That will allow you to install it in the same conduit.
Basically your using class 1 wiring methods on a class 2 power source. Then calling it a class 1 ciruit.

Now class 1 speaker wire ? doubtful. Another class 1 type of cable that is class 1 rated ? Possible
Good idea ? - NO
Legal - Yes as long as you do everything that is in the exception


----------



## wildleg

manchestersparky said:


> According to 725.130(A) exception No. 2- you could reclassify the class 2 circuit to a class 1 circuit. That will allow you to install it in the same conduit.
> Basically your using class 1 wiring methods on a class 2 power source. Then calling it a class 1 ciruit.
> 
> Now class 1 speaker wire ? doubtful. Another class 1 type of cable that is class 1 rated ? Possible
> Good idea ? - NO
> Legal - Yes as long as you do everything that is in the exception


if you are going to make it a class 1 wiring system, the power source must be reidentified as a class 1 power source (if it is identified as a Class 2 then that marking must be changed/re-labeled). 725.130 A ->725.124


----------



## Big John

Even re-classifying it as Class 1 is not a free pass. It still needs to be "functionally associated" when pulled in the same raceway. I know I've stretched that definition to the breaking point myself, but it'd be a hard fight claiming that the speakers and lighting were associated wiring.


----------



## manchestersparky

wildleg said:


> if you are going to make it a class 1 wiring system, the power source must be reidentified as a class 1 power source (if it is identified as a Class 2 then that marking must be changed/re-labeled). 725.130 A ->725.124


Yes -thats why I stated you need to follow all the items in the exception


----------

