Fire Alarm in Hazardous Locations

New research Lab with H2 and H3 Hazardous Rooms occupancies , it is electrically classified per NFPA 70, Article 500, the question is about the fire alarm devices in these rooms, do the FA devices required to be electrically classified or not? the designer is claiming that these devices are of low voltage and not creating a hazard , therefore it is not required to be of classified . Your insights are highly appreciated.

low voltage still creates a hazard. they will need explosion proof devices, wiring, compression fittings, etc.

best case scenario, if it’s a class2 div2 area and if it’s horn strobes, they can go with sti-usa STI-1229-HAZ enclosures and put their normal FA devices in them. if it’s class2 div2 voice they will need to get explosion proof speakers and put their normal strobes in the STI-1229-HAZ enclosures.

if it’s class1 they’ll need different devices which won’t sync and have high current so they’ll require dedicated circuits and it all gets very expensive very quickly.

if detection is required, they’ll either need explosion proof heats or an air aspirating detector (vesda). again, none of these options are cheap… which is why the designer is wanting to avoid them.