Pressure switches are installed downstream
of both anti-ice modulating shutoff valves.
These switches operate in conjunction with a
low wing temperature signal from the overheat
sensor to illuminate the appropriate amber L
or R FAIL LIGHT.
There are two control sensors in each wing.
The temperature control sensors send tem-
perature information to the anti-ice controller.
The anti-ice controller uses the higher of the
temperatures to modulate both valves to main-
tain a temperature at the sensor of 190°F. The
anti-ice controller is powered from DC bus 1
and 2.
The temperature sensor will detect sufficient
heat (85°F) and will turn on the white HEAT
lights. If the overheat sensor detects an over-
heat condition (265°F), it will illuminate the
OVHT light.
Failure of any of these four sensors with the
wing anti-ice selected to normal will illumi-
nate the sensor fail light.
Two standby thermal switches, one in each
wing, will open or close their respective wing
anti-icing shutoff valve. With the wing anti-
ice switch in STANDBY mode, the valve will
open at 120°F or less and close at 180°F. The
anti-ice controller is bypassed in this mode,
and the modulating valves are powered by the
battery bus and the DC essential bus.
Controls and Indicators
The NORMAL or STANDBY mode is selected
with a WING switch on the upper left of the
anti-icing control panel. The switch has three
positions: STANDBY, OFF, and NORMAL. In
the NORMAL mode, both modulating valves
open and operate automatically according to
signals supplied by the anti-icing controller.
The controller modulates the valves as re-
quired to maintain the leading-edge temper-
ature at 190°F. When the STANDBY position
is selected, the anti-ice controller is bypassed
and the modulating shutoff valves are ener-
gized directly to the fully open position or the
fully closed position by the thermal switches
at a temperature of 120-180°F.
A short time after the wing anti-icing system
is activated, the white lights labeled “L HEAT”
and “R HEAT” illuminate on the anti-icing
control panel to indicate that there is sufficient
heat in the system for minimum operation.
These lights will extinguish if the leading-
edge temperature drops below 85°F.
An amber left or right FAIL light illuminates
in flight when both pressure and temperature
for adequate leading-edge heating are insuf-
ficient. On the ground, the fail light illuminates
FlightSafety Canada
L t é e
L t d .
CL-600-2B16 PILOT TRAINING MANUAL
CL 601-3A/R
10-7
FOR TRAINING PURPOSES ONLY
LOW
Figure 10-7. Wing Anti-icing Controls and
Indicators