Class 1 and Class 2 wiring through the same panel knockout?

[Jon456]

I'm setting up structured wiring for an alarm system. Inside a utility closet, there is a wall with open studs (sheetrock on the outside only). I will attach a 2' x 4' project board to these open studs to mount the alarm panel, network switch, etc.

Since this utility closet is also used daily for other purposes, I am considering running some of the cabling behind the board in the bay created by the open studs. This will minimize the amount of cabling on the face of the board to give the board a cleaner look and also reduce the risk of damage to the cables over time. The alarm control panel comes in a locking steel enclosure, and there's a knockout in the back of the enclosure. I could install a rigid chase nipple in this knockout and through a hole in the mounting board behind the panel. Then I could run cables out the back of the panel, up the bay between the studs to above the drop ceiling, and then route them to the various alarm sensors.

So what about the 120v power cord for the alarm control panel: can it also pass through this same knockout? I know that Class 1 and Class 2 wiring cannot share a raceway, but is a single chase nipple considered a raceway?

 

[hbiss]

Not a matter of Class 1 and 2 but of one being flexible cord for the line cord. Any alarm panel I have ever seen is powered by an external 24V transformer, usually of the wall wart type. If yours does have a line cord, it could be run through the same knockout but that's where it ends. Line cords cannot be run through walls or even fastened to it. I would suggest running it through another knockout on the side of the enclosure, installing a receptacle on the board or wall and plugging the line cord into it. You cannot fasten the line cord to the board or wall, but you can bunch any slack up and use a Ty-Rap to hold it together.

-Hal

 

[Jon456]

Thanks Hal,

This particular alarm panel has the low-voltage power supply built into the control panel. There's a port on the side of the control panel (within the enclosure) for plugging in the line cord; the line cord is included with the panel.

I wasn't planning to run the line cord within a wall. There is no enclosed wall; it's open studs inside the utility room (with the outside of the studs sheathed in sheetrock. If a piece of plywood is placed on the studs but is open at the top and bottom, does that now constitute an enclosed "wall"? I don't see how this is different than running a line cord behind an appliance or piece of furniture.

If I run the line cord out the side of the enclosure (using a cord connector/strain relief) the cord cannot be attached to the face of the mounting board, even with something non-permanent like zip ties or velcro cord wraps?