曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
“PUMP ON” legend on the oil replenishment panel goes out (indicating pump stoppage).
Also confirm that the “VLV OPEN” legend on the oil replenishment panel goes out (indicating
valve closure).
· Select the “POWER” switch, “SYSTEM ON” legend extinguishes. Record the amount of oil
added and a walk around for external leakage (oil overfill) should be carried out.
AUXILIARY POWER UNIT
REV 41, Jul 08, 2004 Flight Crew Operating Manual
CSP 700−6
Volume 2
05−10−7
FUEL CONTROL AND INDICATION
The fuel system is a fully automatic electronic control system. The fuel control unit provides metered
fuel to 10 fuel dual orifice nozzles regulated by signals received from the FADEC.
During start, the fuel system provides the correct amount of fuel to support combustion and for
smooth acceleration of the engine to full rated speed. Once rated speed is reached, fuel flow is
modulated as necessary to meet the demands of varying pneumatic and electrical loads, while
maintaining a constant speed.
Airframe Fuel
Fuel is normally supplied to the APU from the right engine feed line or from the left engine feed
line by opening the crossfeed shutoff
valve. The left example below represents APU start
operation with battery electrical power. The right example below represents APU onspeed
operation with AC electrical power. For further information on the airframe fuel system operations,
refer to the FUEL SYSTEM Chapter of this manual.
GF0510_006
APU starting and no main
engines running:
The right AUX pump supplies
the APU through the right
engine feed line.
APU on−speed and main
The right
PRI pumps feed the APU
through the right engine feed
line.
engines running:
FUEL
P P
TOTAL FUEL
38400 LBS
FUEL USED
300 LBS
14600 LBS 14600 LBS
9200 LBS
0 LBS
AUX AUX
23 °C 23 °C
32 °C 32 °C
APU
P P
FUEL
P P
TOTAL FUEL
38400 LBS
FUEL USED
300 LBS
14600 LBS 14600 LBS
9200 LBS
0 LBS
AUX AUX
23 °C 23 °C
P P
LO PRESS LO PRESS
APU
P
32 °C
P
P
32 °C
P
P
P
P
P
AUXILIARY PUMP
CROSSFEED
SHUT−OFF
VALVE
PRIMARY
PUMPS
P
P
P
P
AUXILIARY POWER UNIT
Flight Crew Operating Manual REV 41, Jul 08, 2004
CSP 700−6
Volume 2
05−10−8
FUEL CONTROL AND INDICATION (CONT'D)
Ignition
The ignition system consists of a dual output ignition unit, two (2) ignition leads and two (2) igniter
plugs. There are two cycles of operation: “BURST” for starting (at 5%) and “MAINTENANCE” for
acceleration (duration of the start).
The ignition system is fully automatic and controlled by the FADEC. Ignition occurs at 5% APU
RPM.
During APU operation in nonessential
mode (ground operation), ignition is terminated at 50%
RPM. During essential mode (in flight), ignition is terminated at 98% RPM.
Should flameout occur during operation, the ignition unit will automatically start through the “Auto
Relight” function of the FADEC.
Start System
Operation of the starter is automatically controlled by the FADEC, through the APU control switch.
Starter operation begins by selecting the START position on the APU control panel. At sea level,
starter cutout occurs at 46%. At altitude, starter cutout may be as high as 60% APU RPM to
ensure a positive start.
The starter is capable of an immediate restart on roll down when APU RPM is at or below 7%
RPM.
Speed Indication
Two speed sensors provide indicated speed for onspeed
control and overspeed APU protection.
During operation, the FADEC monitors the input and should either sensor fail, there will be an APU
FAULT advisory message displayed on EICAS.
A failure of either sensor will not cause an APU protective shut down to occur.
Temperature Indication
The EGT system consists of a single temperature sensing unit with two (2) probes. The probes
provide redundant signals to the FADEC for fuel schedule trim, turbine temperature monitoring and
Load Control Valve (LCV) modulation. The APU is protected from overtemperature during
acceleration by protective features incorporated in the FADEC.
Loss of one probe will not affect APU operation.
In the nonessential
(ground) mode, failure of both probes will cause the FADEC to shut down the
APU and inhibit start.
In the essential (in flight) mode, failure of both probes will not cause a shut down. Instead, the
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
庞巴迪挑战者手册6(84)
