Ground Operation - BOMBARDIER Challenger 601-3A CL-600-2B16 Pilot Training Manual

NOTE
The left and right engine bleed-air
switches must remain off. Selecting
the left switch or selecting the right
switch and isolation valve switch will
automatically close the APU LCV.
Air from the bleed-air manifold to the ACUs
is controlled by the left and right ACU switch-
lights (Figure 11-2). The OFF lights will ex-
tinguish to indicate switch selection, and the
FAIL lights will illuminate only when there is
a malfunction. The system is now in operation
for ground heating or cooling, depending on
the temperature selection.
Figure 11-5 shows the air-conditioning airflow
schematic. Refer to this figure while studying
the system operation.

GROUND OPERATION

Initially, the APU supplies the 10th-stage
bleed-air manifold. The isolation valve is se-
lected open and air from the manifold is di-
r e c t e d t h r o u g h t h e l e f t a n d r i g h t AC U
pressure-regulating and shutoff valves. The
ACU valves are operating in the high mode.
From here on, the operation of the right ACU
will be described. Operation of the left ACU
is identical. From the ACU valve, the hot bleed
air passes through the precooler. The WOW
system has opened the jet pump (ejector) valve,
inducing ambient air from the ram-air intake
through the precooler and heat exchangers.
From the precooler, the flow will be through
the primary heat exchanger and then to the
ACU compressor where a pressure and tem-
perature increase occurs. Outflow from the
ACU compressor is directed through the sec-
ondary heat exchanger where temperature is
reduced but pressure is not. This airflow is then
directed through the expansion turbine where
expansion and cooling occurs. The air passes
through the water separator and on to the tem-
perature control system. Here, mixing of hot
air and cold air results in conditioned air at a
selected temperature. This conditioned air is
11-6 CL 601-3A
CL-600-2B16 PILOT TRAINING MANUAL
directed to the cabin conditioned air outlets.
The crossover, or balance, ducts also allow this
air to enter the cockpit conditioned air ducts.
In addition, the cooled airflow from the water
separator goes directly to the cabin cold air out-
lets (gaspers), the cockpit cold air outlets, and
the instrument panel cooling duct.
IN-FLIGHT OPERATION
When the engines are operating, the pilot may
select both engine bleed-air valves open, close
the APU bleed-air and isolation valve and then
proceed to shut down the APU. This will be
the normal method of in-flight operation.
Operation of the system will be similar to that
explained above except that now the engines
are supplying the airflow, and the pressure-reg-
ulating and shutoff valves will operate in the
low mode. If one ACU is selected off, the
other will operate in high mode.
FOR TRAINING PURPOSES ONLY
FlightSafety Canada
NOTE
Unless aircraft is fitted with SB 601-
0450, both ACU switchlights must
be selected OFF prior to starting the
engine.
L t é e
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