Does Wiring to 24V Smoke Damper Actuators have to be Class 2?

[TJLEMAY]

There are a Qty of (186) 24VAC smoke damper actuators that need to be powered at all times under normal conditions. The power to these units will be broken only in the event of a general fire alarm. The HVAC Contractor is going to install the low voltage wiring and I'm providing the transformers.

I am planning to provide .75 and 1.0 kVA 120/240 x 12/24V Tranformers for the HVAC contractor to connect to. The transformers will be fed from a 120V / 20A dedicated branch circuit and I was intending to install in-line fused on the secondary conductors based on the number of actuators the HVAC contractor placed on a circuit. The transformers are not listed Class 2 devices.

The HVAC contractor is telling me I must use Listed Class 2 power supplies. Why?

 

[iwire]

Because if you don't provide class 2 power supplies the HVAC contractor would have to use chapter 3 wiring methods which would raise his costs.