The heat detector in an elevator hoistway must have a setting relative to the sprinkler head rating. It must be set:

• A. Higher than the temperature rating
• B. Lower than the temperature rating
• C. Equal to the temperature rating
• D. Not related to the temperature rating

Answer: (B)

The main idea is to ensure coordination between detection and suppression in an elevator hoistway. The heat detector should be set to respond at a temperature lower than the sprinkler head rating so it activates first. This lets the fire alarm and elevator recall systems trigger before the sprinklers discharge, providing early warning and giving time to safely halt elevator movement and evacuate or evacuate occupants before water is released into the hoistway. If the detector were set higher than the sprinkler rating, the sprinkler could discharge first, increasing water damage and delaying protective actions. Setting it equal to the rating would reduce the lead time for detection, and not being related defeats the purpose of coordinated protection.