What does pre-engineered mean for a kitchen suppression system?
- It is custom calculated by an engineer for each kitchen
- It is assembled at the factory and cannot be altered
- It is designed by the local fire marshal's office
- It is installed within the limits of its listed manual
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D. It is installed within the limits of its listed manual
Nozzle types, pipe lengths, flow points and appliance coverage were all fire tested, and the installer must stay inside those listed limits. No hydraulic calculation is done, but the limits cannot be exceeded.
Reference: NFPA 17A and NFPA 96: wet chemical systems for commercial cooking
How does a typical kitchen system detect a fire automatically?
- A smoke detector in the dining room sends a signal
- A flow switch senses grease moving in the duct
- A fusible link in the hood melts and releases a tensioned cable
- A gas sensor detects unburned fuel at the burner
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C. A fusible link in the hood melts and releases a tensioned cable
Heat detectors, commonly fusible links on a cable line above the appliances and in the duct entrance, separate at their rated temperature and trip the release mechanism. Smoke detectors are not used because normal cooking would set them off.
Reference: NFPA 17A and NFPA 96: wet chemical systems for commercial cooking
When a kitchen suppression system operates, what must happen to the gas or electric supply to the protected cooking appliances?
- It must stay on so cooking can resume
- It must be shut off by the cook by hand
- It must shut off automatically
- It must switch to a backup supply
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C. It must shut off automatically
Fuel and heat sources to the protected appliances shut down automatically on system actuation, by a gas valve or electrical contactor. Leaving the heat on would keep reheating the oil and defeat the agent.
Reference: NFPA 17A and NFPA 96: fuel and power shutoff