GAYLORD CG3 Series Technical Manual page 8

"CG3" SERIES VENTILATOR PRINCIPLE OF OPERATION
INTERNAL FIRE MODE — For CG3 and CG3-FDT only!
Automatic internal fire protection is accomplished by the
action of the thermostat(s), which are located at the point
where the ductwork joins the ventilator. When the temperature
of the conveying airstream, which must pass over the thermo-
stats, reaches 250°F, the system is activated, and the
following occurs:
1. The damper begins closing back to the fire position,
position 3 as shown in Fig.4—stopping the combustion-
supporting, natural draft through the ventilator and creating
a fire barrier to contain the fire in the kitchen. (N/A on CG3-
FDT)
2. The exhaust fan serving the ventilator is shut off. The
supply fan is also shut off.
3. Fire-smothering water spray is released into the interior of
the ventilator through the spray nozzles.
4. The digital display reads "Fire In Hood, Fan Off, Wash On"
for approximately 5 seconds.
5. Then the digital display reads "Fire In Hood, Damper
Closing" for approximately 5 seconds.
6. Then the digital display reads "Fire In Hood, Notify Fire
Department". This display stays on until the thermostat
cools down below 250°F.
CAUTION:
In case of severe fire the thermostats located in the plenum will
activate. As a precautionary measure, it is recommended that
the thermostats be replaced.
7. A red light on the Command Center illuminates.
8. If the Command Center is intertied with a building alarm or
monitoring system, a fire signal would be sent to that
system.
9. Upon cooling of the thermostat below 250
Down Cycle starts. The water continues to spray during
the Cool Down Cycle (2 minutes). The damper moves to
the exhaust position. (N/A on CG3-FDT)
10. While in the cool down cycle the digital display reads
"Cool Down Cycle, xxx sec. to end". xxx is the countdown
in seconds until the wash turns off. The damper moves to
the exhaust position.
11. At the end of the cool down cycle the wash turns off and
the digital display reads "Fan Off 12:00 (actual time), Start
Fan>F1". The damper closes to the wash position. (N/A
on CG3-FDT)
NOTE: The water may be shut off prior to the end of the 2 minute
cool down cycle by pushing the "Exit" button on the C-6000
Command Center. After the water has shut off, the damper
remains in the wash position until the "Start Fan" button is
pushed.
FIG. 4
FIRE CYCLE
8
o F, the Cool