BOMBARDIER BD-100-1A10, Operating Manual

Page: 83 / 544

AIR CONDITIONING/PRESSURIZATION
Sep 13/2004 Flight Crew Operating Manual Volume 2
REV 1 CSP 100-6
02-02-03
BLEED AIR DISTRIBUTION (Cont)
COMPONENTS AND OPERATION
BLEED AIR MANIFOLD
The bleed air manifold is located in the engine pylons and aft equipment bay and is divided into the right side and left side
by the crossbleed (XBLEED) valve. The engines provide bleed air to their respective sides of the manifold and the APU
and ground air cart provide air into the right side of the crossbleed valve.
EXTERNAL GROUND AIR CONNECTOR
An external air connector is located aft of the equipment bay door on the exterior surface of the fuselage.
The external ground air connector and duct are not depicted on the ECS synoptic displays. However, when external air is
connected, the air pressure is displayed as a manifold pressure digital readout on the ECS synoptic page.
CHECK VALVES
Four check valves are installed in various locations in the bleed air ducting.
An intermediate pressure check valve is installed in each engine bleed air duct to prevent reverse flow into the engines.
Check valves are installed at the external air connector and in the APU bleed air duct. The check valve at the external con-
nector prevents the loss of air to the atmosphere. The check valve in the APU duct prevents the reverse flow of manifold
air to the APU when the APU is shut down.
Check valves are not represented on the ECS or A/ICE synoptic displays.
INTERMEDIATE PRESSURE VALVES
Engine bleed air pressure increases proportionally with N
2
compressor speed. The pressure regulating function of the in-
termediate pressure valve limits the engine discharge pressure to 50
±
3 psi. When N
2
compressor speed is low and the
engine bleed air pressure is less than the regulated value, and at least 10 psi or greater, the valve is fully open.
The valves are pneumatically operated and electrically controlled by the L (R) BLEED switches on the air cond/bleed pan-
el.
The bleed air valves are in a closed position when:
- Aircraft engines are shutdown
- Power is lost to valves
- Associated ENG FIRE switch is selected
- Bleed air valves are selected closed at the AIR COND/BLEED control panel.
HIGH PRESSURE VALVES
The high pressure valves regulate the engine high pressure bleed to 36
±
3 psi. This high pressure air is then routed to the
wing anti-ice system.
The valves are pneumatically operated and electrically controlled by the WING SOURCE switch and WING switch on the
ANTI-ICE control panel.
The high-pressure valves are in a closed position when:
- Aircraft engines are shutdown
- Power is lost to valves
- Associated ENG FIRE switch is selected
- Bleed air valves are selected closed at the ANTI-ICE control panel via the WING switch.