Where HVAC systems are required to be interlocked to the fire alarm system and/or duct smoke detectors, the shutdown of the HVAC system shall be hardwired to the HVAC equipment and not rely on the BAS system unless the BAS system is approved for such actions.
Guidance: In general the BAS and fire protection interfaces shall be kept as simple as possible. Required NFPA functions shall only be performed by approved controls
The Building Automation System (BAS) control system shall have a dedicated fire alarm shutdown input to detect the status of the fire alarm shutdown controls. When the BAS system detects a fire alarm shutdown alarms shall be generated and the BAS shall position valve, damper and fan signals to match the hardwired shutdown positions.
The fire alarm shutdown protection shall not override freeze protection control. Guidance: During a fire alarm shutdown, the freeze protection control shall not be inhibited to provide such functions as closing the outside air damper or opening a heating control valve, etc.
Hand-off-auto switches shall never bypass fire alarm shutdown functions unless they are part of an approved smoke/fire control system.