Volume air valve vs. fire dampers

[randomkiller]

How exactly do the air handlers tie into the circiut in order to make them interlock. Do they tie in parallel with the relay that is controlled by the f.a.c.p. or will they be set alone on their own relay

There typically isn't an interconnect from the smoke dampers to the air handler. The FACP and or smoke detectors (smaller install) do have a relay board(s) that operates fan kill in a smoke or fire condition. Combustion air dampers are tied into fossil fuel burning equipment through and end switch to prove the damper is open before combustion.