You're on the right track, but there are crucial details and best practices to consider to ensure safety and compliance. Here's a breakdown of how to approach this, along with important warnings

Key Steps & Considerations:

1. Code Compliance (MOST IMPORTANT)



NFPA 96 (Ventilation Control and Fire Protection of Commercial Cooking Operations)

This is the governing standard for commercial kitchen fire safety. It covers gas shut-off requirements extensively. Consult this standard! It often dictates the specifics of your system.

NFPA 72 (National Fire Alarm and Signaling Code)

Addresses the integration of CO detection into the fire alarm system.

Local Building Codes

Always check your local codes and ordinances. They may have specific requirements beyond national standards.

AHJ (Authority Having Jurisdiction)

Talk to your local fire marshal or building inspector. This is critical. They will have the final say on what is acceptable. Get their buy-in early in the process to avoid costly rework.2.

Gas Shut-Off Valve



Dedicated Valve

A dedicated, normally-closed, electrically operated gas shut-off valve is required. This valve MUST be sized appropriately for the gas line.

Valve Placement

The valve should be installed upstream of all gas appliances in the kitchen, as close as possible to the gas meter or regulator.

Valve Listing

Ensure the valve is listed for gas appliance shut-off applications. It should have appropriate approvals (e.g., UL, FM).

Manual Reset

The valve MUST have a manual reset after it trips. This prevents automatic re-energization and requires a person to investigate the cause of the alarm.3.

CO Detector & Fire Alarm Integration



Addressable System

You're correct in thinking about using an addressable relay module from the fire alarm system. Addressable systems provide precise location information.

Supervision

The relay module and the wiring between the fire alarm panel and the gas shut-off valve must be supervised. This means the fire alarm system will alert you if the wiring is cut, shorted, or the relay fails.

CO Detector Listing

Ensure the CO detector is listed for commercial kitchen use and compatible with your fire alarm system. It must meet the required response time specified by the code.

Detector Placement

Placement of the CO detector(s) is critical. Follow the manufacturer's instructions and NFPA 72/96 guidelines. Generally, place them near the appliances, away from direct heat sources, and at the appropriate height.

Programming

The fire alarm panel must be programmed to activate the relay module upon a CO alarm from the detector.4.

Electrical Considerations



Separate Circuits

The gas shut-off valve should be on a dedicated circuit independent of the appliance circuits.

Valve Voltage

Determine the voltage requirements of the gas shut-off valve (typically 24VDC or 120VAC). Choose a fire alarm relay module that matches.

Wiring

Use appropriate wiring methods as required by code. Conduit is generally required for commercial applications.5.

Sequence of Operations

CO Detector Alarms Fire Alarm Panel Receives CO Alarm Fire Alarm Panel Activates Relay Module Relay Module De-energizes Gas Shut-Off Valve (Valve Closes) Gas Flow to Appliances is Interrupted Alarm Sounding (If programmed)6.

Documentation & Testing



Detailed Drawings

Create detailed drawings showing the location of the CO detector(s), gas shut-off valve, fire alarm control panel, and all wiring connections.

Programming Documentation

Document the fire alarm panel programming related to the CO alarm and gas shut-off valve.

Testing

Thoroughly test the system after installation. This should include: Verifying that the CO detector triggers the fire alarm panel. Verifying that the relay module activates the gas shut-off valve. Verifying that the gas shut-off valve completely shuts off the gas flow. Performing periodic testing as required by code (usually monthly or quarterly).

Important Warnings



Never Bypass Safety Devices

Do not attempt to bypass or disable any part of the safety system.

Qualified Professionals

This work must be performed by qualified and licensed professionals:

Fire Alarm Technician

For the fire alarm system integration.

Licensed Plumber/Gas Fitter

For the gas line and valve installation.

Licensed Electrician

For the electrical wiring.

Improper Installation is Dangerous

Improper installation can lead to gas leaks, explosions, and/or system malfunctions.

Example Scenario


CO Detector

A listed commercial CO detector is installed near the gas ranges.2.

Fire Alarm Panel

The CO detector is connected to an addressable fire alarm panel.3.

Relay Module

An addressable relay module is connected to the fire alarm panel and programmed to activate on a CO alarm.4.

Gas Shut-Off Valve

A dedicated, electrically operated, normally-closed gas shut-off valve is installed in the gas line feeding the gas ranges. This valve is sized properly for the gas line.5.

Wiring

Supervised wiring connects the relay module to the gas shut-off valve.6.

Alarm

If the CO detector detects elevated CO levels, it sends an alarm signal to the fire alarm panel.7.

Shut-Off

The fire alarm panel activates the relay module, which de-energizes the gas shut-off valve, closing the valve and shutting off the gas supply to the ranges.8.

Manual Reset

The system requires a manual reset at the gas shut-off valve after the cause of the alarm has been addressed.

Answering Your Specific Questions



Addressable Control Relay

Yes, using an addressable control relay from the fire alarm system to the master shut-off valve is the correct approach. Ensure it is supervised and sized for the valve's voltage requirements.

Appliance Breakers

You are correct that the 120V/20A breakers for the appliance ignition should not* be turned off. Shutting off the gas supply is the primary safety measure. The ignition circuits are still needed if the system resets and the ranges are used again.

In summary, prioritize code compliance and work with qualified professionals. The AHJ is your best resource for ensuring a safe and compliant installation. Flag for review