"hand" mode, the damper should be controlled by an
open-stop-close pushbutton set. The damper should be capable of
infinite positioning in either mode of operation.
a) Motorized dampers connected to the DTC in the
control. Damper position status should be provided in the
instructor's station. Floating point dampers should be provided
with a modulating control output and the two position dampers
should have binary control. See Appendix A, Figures A-18 and
b) Variable speed motor should be provided for the
primary fan in each system, so the fan can be economically
turned down during periods of no fire. This control would
operate from reduced flushing flow to fully open when directed
by the device computer. Any control used should have the
(1) Modulation controls should have positive
feedback and interface with the DTC.
(2) Exhaust fan controls should provide means to
indicate in the instructor's station the following status:
Fan on-off condition
Fan modulation - rpm (only if variable speed
control is used)
Alarm air temperature
Exhaust air temperature
(3) The exhaust system should be provided with
safety warning signs to indicate personnel hazard from heat of
c) A manual damper should be located in the duct
leading from all compartments so the maximum exhaust flow from
that space can be limited.
d) Dampers should be designed for high temperature
operation at 538 degrees C. High temperature dampers should be
constructed of stainless steel, same material as the ductwork.