Emergency Pressurization; Air Source; Control; Operation - BOMBARDIER Challenger 601-3A CL-600-2B16 Pilot Training Manual

EMERGENCY
PRESSURIZATION
GENERAL
An emergency pressurization system must be
used if the air-conditioning system is inca-
pable of providing normal pressurization. This
may be caused, for example, by a ruptured or
leaking bleed-air manifold.

AIR SOURCE

The source of air for emergency pressurization
is directly from the left engine high-pressure
compressor. The system is integrated with the
footwarmer-windshield demist system in that
it utilizes the left footwarmer-demist pres-
sure regulating and shutoff valve and heat ex-
changer. (See Chapter 9, "Pneumatics.")
The left footwarmer-demist shutoff is nor-
mally controlled by the STBY position of the
CKPT HEAT switch on the bleed-air control
panel but can also be energized from the EMER
PRESSN switch.

CONTROL

The emergency pressurization system is con-
trolled by a guarded switchlight on the pres-
surization control panel (Figure 12-1) labeled
"EMER PRESSN." An amber ON light in the
switch will illuminate when the switch is
pushed. This switch energizes two valves: (1)
the left footwarmer-demist pressure regulating
and shutoff valve (regardless of the position of
the cockpit heat switch) and (2) an emergency
pressurization shutoff valve that connects the
footwarmer-demist duct to the cockpit and
cabin conditioned air ducts. The valves re-
quire pneumatic pressure to actually open.
The power supply for emergency pressuriza-
tion control is from the battery bus.
12-8 CL 601-3A
CL-600-2B16 PILOT TRAINING MANUAL

OPERATION

Figure 12-5 illustrates operation of the emer-
gency pressurization system. Notice that all
normal bleed-air valves are closed. An air
supply directly from the left engine is routed
through the left footwarmer-demist valve to the
heat exchanger. Ram-air crossflow tempers
the hot air supply. The ram crossflow is con-
trolled by a temperature control valve in the
heat exchanger exhaust duct. The valve is po-
sitioned by a temperature bulb located in the
bleed duct downstream of the heat exchanger.
The tempered airflow to the footwarmer-
demist plenum enters the conditioned air ducts
through the emergency pressurization shut-
off valve for distribution to the cabin and cock-
pit. The normal temperature control panel has
no effect on cabin and cockpit temperatures
during emergency pressurization. The foot-
warmer and demist controls (Figure 12-6) can
be used as required.

CABIN ALTITUDE CONTROL

Cabin altitude and rate-of-change controls are
available through either the automatic selec-
tor in the automatic mode or through the MAN-
ual REGulator in the manual mode as long as
electrical power required for normal pressur-
ization is available.
FOR TRAINING PURPOSES ONLY
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