BLEED-AIR SYSTEM
COMPONENTS
BLEED SWITCHES
The L and R BLEED switch/indicators (Figure
9-1) are used for independent control of left
and right engine bleed-air supply. Each S/I is
a momentary action switch that illuminates
“OFF” when not selected, and is blank when
depressed/selected to the ON position. See
Table 9-1 for a summary of the valves affected
by the BLEED switches.
ECS CONTROLLER
The ECS Controller is installed in the tail-
cone and contains the circuitry required to
operate the ECS SOVs, the HP SOVs and the
Emergency Pressurization valves (Figure 9-3).
The ECS Controller is dual channel, control-
ling bleed-air supply from both the right and
left engines independently. The left channel
controls the left ECS PRSOV, left HP SOV
and the left Emergency Pressurization Valve;
the right channel controls the same valves on
the right side. The controller channels receive
independent inputs from pressure sensors in
t h e H P d u c t s , t h e C a b i n P r e s s u r i z a t i o n
Controller, Thrust Lever angle, BLEED switch
position and EMER PRESS switch position.
The left and right channels of the controller
receive 28 VDC from the left and right es-
sential busses respectively through the L
BLEED and R BLEED circuit breakers. The
circuit breakers can be found in the ENVI-
RONMENTAL group of circuit breakers on the
respective circuit breaker panels. The circuit
breakers provide power through the ECS con-
9-3
FOR TRAINING PURPOSES ONLY
L E A R J E T 4 5
P I L O T T R A I N I N G M A N U A L
FlightSafety
international
ON
DEPLOY
OFF
PAX
OXY/AUTO
PAX OXYGEN
ON
MANUAL
PRESS
ON
EMER
DEPRESS
OFF
L BLEED
ON
EMER PRESS
OFF
R BLEED
ON
HI FLOW
OFF
PACK
ON
APU BLEED
3 5 0
I . 2
I 3 0 0
CABIN PRESSURE CONTROL
CAB RATE
DELTA P
CAB ALT
FPM
PSID
FT
LDG ALT
DN
UP
MANUAL
DN
UP
PRESSURIZATION
Figure 9-1. Pressurization/Oxygen
Control Panel