DIYbanter - View Single Post - Mixing high & low voltage wires in electrical conduit?

writes:
On Wed, 06 Jul 2005 13:31:10 GMT, blueman wrote:

Is it allowed to run both 110v wire (either THHN or Romex) and low
voltage alarm wire (e.g., 4 conductor 22 gauge) in the same 1/2" rigid
metal conduit?

I probably will have one 2-conductor #14 Romex wire for overhead
garage light plus a couple of alarm cables for the window, door, and
heat sensors.

Thanks

This is what the code says;

725.55 Separation from Electric Light, Power, Class 1,
Non–Power-Limited Fire Alarm Circuit Conductors, and Medium Power
Network-Powered Broadband Communications Cables.
(A) General. 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, non–power-limited fire
alarm circuits, and medium power network-powered broadband
communications circuits unless permitted by 725.55(B) through (J).
Section 725.55(A) specifically includes cables of Class 2 and Class 3
circuits. Jackets of listed Class 2 and Class 3 cables do not have
sufficient construction specifications to permit them to be installed
with electric light, power, Class 1, non–power-limited fire alarm
circuits, and medium power network-powered broadband communications
cables. Failure of the cable insulation due to a fault could lead to
hazardous voltages being imposed on the Class 2 or Class 3 circuit
conductors.
(B) Separated by Barriers. Class 2 and Class 3 circuits shall be
permitted to be installed together with Class 1, non–power-limited
fire alarm and medium power network-powered broadband communications
circuits where they are separated by a barrier.

So if I am reading the code English properly, what I am asking is not
allowed even if the 110v (Class 1) wires are enclosed in Romex cabling
unless there is some additional "barrier" between the power and alarm
wires.
Right?