Class 1 or 2 wiring at 24 VDC

I have a consultant that assures me there is a requirement to inatall class one wiring all the way to the load if the power source is rated at over 100 va. This is supposedly the case even if the power source is fused down to 1/2 amp at 24 VDC, or 12 watts, as long as the source of the power is over 100 va. Now there are a few thousand systems out there that have 140 or 240 va 24 volt A/C and D/C transformers with 300 volt rated 2 conductor cable running camera systems, HVAC, door control etc. Is there an exclusion to this requirement anywhere? I cannot believe that every inspector that I have run accross has missed this.

I can take my answer off the air. Thank you.