How does a fire alarm system coordinate with elevators during an evacuation?

• A. By triggering automatic door opening to vent smoke.
• B. By sounding only the annunciator without moving elevators.
• C. By disabling all signals to elevators.
• D. By sending recall commands via the FACP to bring elevators to a designated floor and hold or return.

Answer: (D)

During a fire alarm, the system coordinates elevator use by sending recall commands from the Fire Alarm Control Panel to the elevator control system. This directs the elevator cars to a designated floor (often a safe or main floor) and puts them into fire service mode, where the cars are held or returned to that floor and regular passenger calls are limited. This setup keeps elevators out of normal service during the emergency and ensures they are available for firefighters or for controlled evacuation as designed, while preventing occupants from riding through smoke and heat or becoming trapped on intermediate floors.

This approach is safer and more effective than other options because it actively manages vertical movement instead of just issuing alerts or disabling signals. Venting doors or triggering announcements without moving the elevators doesn't address the danger of using lifts in a fire, and simply disabling signals would remove the elevator’s controlled response entirely, leaving vertical access unmanaged. The recall to a designated floor provides a controlled, predictable state for elevators during an evacuation or firefighting response.