Low and Line voltage

[Ryan Currin]

I have a circuit in an underground raceway feeding a GFCI outlet under a gas burner station in a restaurant. We now have to install low voltage heat detectors under these units that are connected to a fire suppression control panel. The relay output on the detector is 24 volts and will then shut down power to the GFCI under alarm conditions. Is this low voltage circuit considered class 2? I believe it is class 1 because it is a signaling circuit, and the powered equipment is functionally associated with all the circuits. If all these conductors have an equal insulation rating, can I install them in the same conduit?

 

[don_resqcapt19]

I have a circuit in an underground raceway feeding a GFCI outlet under a gas burner station in a restaurant. We now have to install low voltage heat detectors under these units that are connected to a fire suppression control panel. The relay output on the detector is 24 volts and will then shut down power to the GFCI under alarm conditions. Is this low voltage circuit considered class 2? I believe it is class 1 because it is a signaling circuit, and the powered equipment is functionally associated with all the circuits. If all these conductors have an equal insulation rating, can I install them in the same conduit?

Class 1, 2 and 3 are all signaling circuits. You need to know the rating of the power supply for the 24 volt system. Also is the fire suppression system part of a fire alarm system and covered by Article 760?

 

[Ryan Currin]

low voltage

low voltage

The rating of the supply is 5.4 amps @ 24vdc. The suppression system is part of a fire alarm system.

 

[don_resqcapt19]

The rating of the supply is 5.4 amps @ 24vdc. The suppression system is part of a fire alarm system.

You need to look at the rules in Article 760. They cover the wires that are part of a fire alarm system. You need to know if the fire system is power limited or non-power limited, but I don't think you will find a permission to mix the wires in either case.
My question about the transformer only applied if the conductors were not part of the fire alarm system. If they weren't, you would need to look to see if it is marked as a "Class 2" system.