DIFF PRESS SENSOR ELEV PCA (MIDDLE)
28V DC
L BUS
PCU MONITOR
MODULE
115V AC
L BUS
PCU MONITOR
SENSOR
P11
FROM CTRL VLV
~ P
>1140PSI
DIFF PRESS SENSOR ELEV PCA (OUTBD)ACTUATOR
ELEVATOR(LEFT)
INTERNALS SAME ASTO CONTROL
L OUTBD ELEVSURFACE
DIFF PRESS SENSOR ELEV PCA (MIDDLE)
INTERNALS SAME ASL OUTBD ELEV
DIFF PRESS SENSOR ELEV PCA (INBD)
INTERNALS SAME ASL OUTBD ELEV
DIFF PRESS SENSOR RUDDER PCA (UPPER)
INTERNALS SAME ASRUDDER L OUTBD ELEV
DIFF PRESS SENSOR RUDDER PCA (LOWER)
INTERNALS SAME ASL OUTBD ELEV
DIFF PRESS SENSOR RUDDER PCA (MIDDLE)
GND
NOTES:
1
INDICATES FAILURE OF PCU
MONITOR MODULE OUTPUT SWITCH
AIR
AIR/GND RLY
Rudder/Elevator PCU Monitor SystemFigure 6
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
27-23-00
ALL ú ú 01 Page 7 ú Jan 28/02
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
757
MAINTENANCE MANUAL
AFT FIRE WALL
SEE A
ELEVATER CENTERHYDRAULIC SYSTEM FUSES
SEE B
ELEVATOR CENTER HYDRAULIC SYSTEM FUSES
A
ELEVATOR CENTER HYDRAULIC SYSTEM FUSES
B
Elevator and Rudder Center Hydraulic System Fuses Figure 7 (Sheet 1)
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
27-23-00
ALL ú ú 02 Page 8 ú Jan 28/02
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
757
MAINTENANCE MANUAL
311AL
RUDDER CENTER HYDRAULIC SYSTEM FUSE
SEE C
RUDDER CENTER HYDRAULIC SYSTEM FUSE
C
Elevator and Rudder Center Hydraulic System Fuses
Figure 7 (Sheet 2)
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
27-23-00
ALL ú ú 15 Page 9 ú Mar 20/90
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
(2)
(3)
757
MAINTENANCE MANUAL
(b)
As the valve reaches the open or closed position, internal limit switches open the motor circuit and de-energize the motor.
(c)
There are no return lines for the valves; the isolated system
has residual pressure of 3000 psig.Rudder/Elevator Power Control Actuator Monitor System
_____________________________________________________
(a)
The PCA monitor senses a hydraulic pressure differential across the PCA cylinder that exceeds 1140-1350 psi. If this occurs, the monitor sends a voltage discrete output to the PCA module. The discrete output continues until the pressure differential decreases below 900 psi.
(b)
The PCA monitor module requires that the monitor's discrete output be present for 190-240 milliseconds before sending a failure signal to the EICAS computers. This eliminates false alarms caused by temporary pressure increases. The module detects faults with the following conditions: airplane on the ground with airspeed less than 50 KIAS and all hydraulic systems on. The module also detects open circuit and short to ground failures of sensor and sensor wiring.
Rudder and Elevator Center Hydraulic System Fuses
_________________________________________________
(a)
The rudder and elevator center hydraulic system fuses operate by spring-action. The fuses close when the pressure drop across the fuse increases due to an increased flow from a failed component or line rupture downstream. The fuse automatically resets by its spring-action once the pressure on both sides of the fuse is equal.
(b) 中國航空網 www.k6050.com 航空翻譯 www.aviation.cn 本文鏈接地址：757 AMM 飛機維護手冊 飛行操縱 FLIGHT CONTROLS 2(98)
