P/N 13772-151
45 of 52
Cirrus Design
Section 9
SR22T
Supplements
System Control
System operation is controlled by five bolster panel switches and three
MFD softkeys:
• Bolster Panel Switches: Metering pump operation and mode
control (flow rate) are controlled by the NORM, HIGH, and MAX
switches. WINDSHLD controls the windshield pump operation.
PUMP BKUP is used in the event of certain system failures.
• MFD Softkeys: Tank selection is provided by three MFD softkeys
on the MFD Engine Page. Automatic tank selection is provided
by the default, AUTO mode. While the system is operating, the
fluid quantity in each tank will be passively balanced by
alternating the selected tank using the 3-way control valve.
Mode Control
• NORM controls both pumps to operate quarter-time
intermittently to provide 100% flow rate, i.e. 30 seconds on, 90
seconds off.
• HIGH controls #1 pump to operate continuously to provide
200% flow rate, i.e. two times the normal flow rate.
• MAX controls both pumps to operate continuously for 2 minutes
to provide 400% flow rate, i.e. four times the normal flow rate.
Pump operation then reverts to the system mode selected by
the ICE PROTECT Mode Switch.
• WINDSHLD controls the windshield pump to operate
continuously for approximately 3 seconds.
• PUMP BKUP controls #2 pump to operate continuously to
provide 200% flow rate, i.e. two times the normal flow rate.
When pump backup mode is selected, an alternate circuit by-
passes the Timer Box and supplies power to the #2 metering
pump which in turn operates continuously.
Fluid Tank Control
• AUTO: While the system is operating, the fluid quantity in each
tank is passively balanced by the avionics system using the 3-
way control valve and the sensed quantity of each tank.
• LEFT: Ice protection fluid is drawn from the left tank regardless
of sensed quantity.
Original Issue: 02-01-13
