New one for me

That’s what I’m trying to point out. If somebody sees high voltage and low voltage in the same component, they call it out, they may not be correct.

We can go into a whole lot more reasons why you should not do it, but that’s not the point.

I’m sure you’re not implying that low-voltage insulation cannot handle 101° Fahrenheit. If so, what the hell do they do in Arizona!

From the link provided:

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).

(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. **

© Raceways Within Enclosures. In enclosures, Class 2 and Class 3 circuits shall be permitted to be installed in a raceway to **separate them from Class 1, non–power-limited fire alarm and medium power network-powered broadband communications circuits.
**
(D) Associated Systems Within Enclosures. Class 2 and Class 3 circuit conductors in compartments, enclosures, device boxes, outlet boxes, or similar fittings shall be permitted to be installed with electric light, power, Class 1, non–power-limited fire alarm, and medium power network-powered broadband communications circuits where they are introduced solely to connect the equipment connected to Class 2 and Class 3 circuits, and where (1) or (2) applies:
**
(1) The electric light, power, Class 1, non–power-limited fire alarm, and medium power network-powered broadband communications circuit conductors
are routed to maintain a minimum of 6 mm (0.25 in.) separation from the conductors and cables of Class 2 and Class 3 circuits.
**
(2) The circuit conductors operate at 150 volts or less to ground and also comply with one of the following:

a.** 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 6 mm (0.25 in.) or by a nonconductive sleeve or nonconductive barrier from all other conductors. **
b. The Class 2 and Class 3 circuit conductors are installed as a Class 1 circuit in accordance with 725.21.

(E) Enclosures with Single Opening. Class 2 and Class 3 circuit conductors entering compartments, enclosures, device boxes, outlet boxes, or similar fittings shall be permitted to be installed with Class 1, non–power-limited fire alarm and medium power network-powered broadband communications circuits where they are introduced solely to connect the equipment connected to Class 2 and Class 3 circuits. Where Class 2 and Class 3 circuit conductors must enter an enclosure that is provided with a single opening, they shall be permitted to enter through a single fitting (such as a tee), provided the conductors are separated from the conductors of the other circuits by a continuous and firmly fixed nonconductor, such as flexible tubing.

Doesn’t sound like that installation meets the conditions specified.

Agreed. If the equipment is designed/engineered to have them both in same space, and are tested and approved as such, then no issue. Although there will most likely still be some separation devices/barriers within the equipment to prevent accidental interconnection of the voltages.

You are absolutely right. When we were doing this back in 2000, we would install a separator in a three gang box with a hole drilled to fit the 1/2" knock out connector on the low volt transformer. The separator is in the pic below. I completely forgot about those. That’s what I get for trying to recall a 15 year old memory\:D/

I’ve gotten so used to putting it on a metal JB at the furnace, it’s just so much easier to do.