Identify a method to ensure an elevator is de-energized before sprinkler system activation in an elevator shaft.

Identify a method to ensure an elevator is de-energized before sprinkler system activation in an elevator shaft.

• A. A heat detector is placed within 24 in. of the sprinkler head and rated at a lower temperature.
• B. A smoke detector is installed within 10 ft of the elevator machine room.
• C. A pressure relief valve is installed on the sprinkler piping.
• D. A vibration sensor is mounted on the elevator car.

Answer: (A)

Coordinating detection and elevator control so the elevator is shut down before water starts to flow is the key idea. Placing a heat detector near the sprinkler head and rating it to trigger at a lower temperature ensures heat is detected earlier than the sprinkler head would release water. When this detector activates, it initiates the elevator recall and de-energization sequence, moving the car to a safe floor and cutting power to the hoistway. This early response protects occupants and equipment and helps prevent the elevator from operating in a fire or when sprinkler water is about to discharge. A smoke detector near the machine room doesn’t guarantee the same reliable, timely interlock with the sprinkler system, and may react to smoke rather than heat or be triggered too late relative to sprinkler activation. A pressure relief valve on the sprinkler piping doesn’t influence elevator operation, and a vibration sensor on the elevator car doesn’t provide the necessary interlock to de-energize the system during a fire.

Coordinating detection and elevator control so the elevator is shut down before water starts to flow is the key idea. Placing a heat detector near the sprinkler head and rating it to trigger at a lower temperature ensures heat is detected earlier than the sprinkler head would release water. When this detector activates, it initiates the elevator recall and de-energization sequence, moving the car to a safe floor and cutting power to the hoistway. This early response protects occupants and equipment and helps prevent the elevator from operating in a fire or when sprinkler water is about to discharge.

A smoke detector near the machine room doesn’t guarantee the same reliable, timely interlock with the sprinkler system, and may react to smoke rather than heat or be triggered too late relative to sprinkler activation. A pressure relief valve on the sprinkler piping doesn’t influence elevator operation, and a vibration sensor on the elevator car doesn’t provide the necessary interlock to de-energize the system during a fire.