According to national codes, what locations require Phase I recall smoke detectors?

• A. Elevator lobby, machine room, and hoistway smoke detectors
• B. Elevator lobby only
• C. Hoistway smoke detectors only
• D. Machine room only

Answer: (A)

Phase I recall is all about safely recalling elevators to a designated floor during a fire so passengers aren’t trapped in the shaft and firefighters can access the building. To make sure this recall happens no matter where a fire starts, codes require smoke detectors in all the areas that can affect the elevator system: the elevator lobby, the hoistway (the shaft itself), and the machine room (where the elevator equipment is).

An elevator lobby detector catches smoke near the area where people most commonly call and access the elevators. A detector in the hoistway senses smoke traveling through the shaft, which is crucial because smoke can rise quickly through the elevator shaft. A detector in the machine room protects the control gear and power systems that operate the elevator, ensuring safe and proper shutdown and recall. Because each of these locations directly impacts whether Phase I recall can be initiated reliably, all three locations are required. That’s why the best answer includes elevator lobby, hoistway, and machine room detectors.