The operating temperature of a fire damper actuating device shall be approximately how many degrees above the normal temperature within the duct system?

The correct answer is based on industry standards for fire dampers, which are crucial components in HVAC systems designed to prevent the spread of fire and smoke through ductwork. The operating temperature of a fire damper actuating device is set to activate approximately 50°F above the normal temperature within the duct system.

This 50°F increment is adequate to ensure that the damper responds effectively to a legitimate fire scenario, where temperatures can rise significantly. By initiating the damper's closure at this temperature differential, the system can help contain smoke and fire, thereby enhancing safety in the building.

Other temperature options, while they may seem sensible, are not as commonly established in current fire safety standards or are excessively high compared to the 50°F threshold. Utilizing this specific temperature differential promotes a timely and reliable response in fire conditions without unnecessary delays or failures in operation.