Motorized louvers shall
be interlocked with the appliance so they are proven in
the full open position prior to main burner ignition and
during main burner operation. Means shall be provided to
prevent the main burner from igniting where the louver fail to open during burner start-up and to shut down the
main burner where the louvers close during burner operation.
[NFPA 54:9.3.7.3]