All sources of fuel or heat to appliances served by the common exhaust duct shall be ________ upon actuation of any protection system in accordance with 4.4.4.

• A. Shut down
• B. Isolate
• C. Alert only
• D. Continue operation

Answer: (A)

When any protection system is actuated in a kitchen ventilation scenario, the immediate action is to shut down all sources of fuel or heat to the appliances that feed the common exhaust duct. The reason is simple: stopping fuel and heat input prevents ongoing combustion and reduces the risk of the fire spreading or re-igniting, especially since multiple appliances share the same duct. By cutting off gas supplies, disconnecting burners or other heat sources, and de-energizing electric heat elements, you remove the energy feeding the fire and give the suppression system the best chance to control the situation. Merely isolating a single appliance or alerting personnel would not fully stop the potential for continued fire growth, and continuing operation would defeat the purpose of the protection system.