For them, I think they just want a visably marked means of shut off of the load. As they show up to a fire, (assuming here, there a few fire-fighters here who could elaborate) one of the first things they do is shut off power in the building, or portions of it. But all of the things on the UPS stay energized... Last set up was a 30kw 208v APC UPS, and lighting inverter (forget what that one was) but also 208v. Fire inspection went like this, "smoke detector, batteries - how do I shut off every electrical source in this room?" Thier sign off holds up occupancy... For a simple class 2 circuit, not worth it. Like I said, fire marshal, not electrical inspector. And, from what I understand, they had a fire in a room and could not shut off power after the batteries, and this is a result of a big pow-wow about it.
(Side note: they often want horn/stobes moved for reasons like this... "If I were sitting at this desk, I would only be able to see half of that strobe." Like the 110 db horn, and the rest of the building in disco lighting is not a clue to lean back a little, and realize the fire alarm in going off. - And, "I realize that is an exit path, but feel that way is a better way out, you'll need to change the arrows to that direction." Special order arrow specific signs, and change all the escape route signage. If they have to come back, they'll start changing more stuff. Or find yourself there predawn with a lumen meter. Its best to get them out of your hair quick.)
