*
APU EGT in degrees C
*
APU oil pressure in psi
*
APU oil temperature in degrees C
*
APU oil quantity in liters.
Maintenance Page
The APU maintenance page shows the status of many APU systems and the outputs of the APU sensors. The data shown includes:
*
APU pneumatic mode
*
APUC mode
*
Speed sensor input in percent RPM. A box shows for the highest value
*
Exhaust gas temperatures corrected to standard sea level conditions in degrees C
*
Exhaust gas temperatures from each of the two rakes in degrees C
*
Oil pressure in psi
*
Oil temperature in degrees C
EFFECTIVITY
BEJ ALL
*
Oil quantity in liters (LO shows when the quantity is less than 3.50)
*
Inlet static pressure (P2) in psia
*
Load compressor total pressure (exit pressure from the load compressor) in psia
*
Load compressor differential pressure (DP) in psi (difference between the load compressor total pressure and the static pressure downstream of the load compressor)
*
Compressor inlet temperature (T2) in degrees C
*
Oil sump temperature in degrees C
*
Surge control valve position from 90 degrees (fully closed) to 10 degrees (fully open)
*
Inlet guide vane actuator position from 76 degrees (fully closed) to -10 degrees (fully open)
*
Fuel metering unit fuel temperature in degrees C
*
Fuel cluster fuel metering valve position from 0 percent (fully closed) to 100 percent (fully open)
*
Air inlet door command -OPEN or CLOSED (from ELMS)
*
Air inlet door position -OPEN or CLOSED
*
Bleed corrected flow in pounds of air per minute from the load compressor
*
Bleed corrected flow setpoint in pounds of air per minute (calculated by the APUC). This is the surge margin set point
*
APU battery DC voltage and amperage (charging or discharging)
*
APU generator AC voltage, frequency, and load in percentage of maximum load.
APU fuel feed data also shows on the maintenance page. This data includes:
*
APU fuel shutoff valve data
*
DC fuel pump data
49-00-00
Page 29 D633W101-BEJ May 05/2003
AUXILIARY POWER SYSTEM -INDICATIONS
* AC fuel pump data.
The status codes show in digital format (1 or 0) the status of some of the APU inputs and outputs. Refer to section 49-70 in Part II of the airplane maintenance manual (AMM) for more information on the status codes.
APU operating hours and the number of APU starts also shows on the maintenance page.
Training Information Point
You can use the APU maintenance switch to power the APUC when the APU selector is OFF. This permits you to read APU oil system indications on the status display without turning the APU selector to ON.
EFFECTIVITY BEJ ALL 49-00-00
Page 30
D633W101-BEJ May 05/2003
777 AIRCRAFT MAINTENANCE MANUAL
AUXILIARY POWER SYSTEM -INDICATIONS
EFFECTIVITY BEJ ALL 49-00-00
Page 31
D633W101-BEJ May 05/2003
AUXILIARY POWER SYSTEM -APU ACCESS AND SERVICING
APU Access
You get access to the APU compartment through the APU doors.
You open the APU vent doors first to permit air to go into the APU compartment. This makes the pressure equal in the APU compartment and permits you to open the main APU doors when the APU is on.
Each main APU door has a latch on the forward edge of the door. You must release the latches to permit the main APU doors to open. Hold-open rods keep the doors in the open position.
APU Oil Servicing
You add oil to the APU at the oil fill port. The oil level sight gage shows full on the APU OFF side when the oil quantity is at the correct level.
The status display shows the APU oil quantity in liters. The APU maintenance page (not shown) also shows the APU oil quantity.
This is a summary of the procedure to add oil to the APU:
*
Make sure the APU selector on the P5 overhead panel is OFF and attach a D0-NOT OPERATE tag
*
Open the APU access doors
*
Open the oil fill cap
*
Slowly add oil until the oil level is at the FULL mark on the APU OFF side of the oil level sight gage
*
Close the oil fill cap
*
Put the airplane back in its usual condition.
WARNING: DO NOT LET HOT OIL GET ON YOU. PUT ON PROTECTIVE CLOTHES, GOGGLES, AND EQUIPMENT, OR LET THE APU BECOME COOL. HOT OIL CAN BURN YOU.
WARNING: DO NOT LET THE OIL STAY ON YOUR SKIN. YOU CAN ABSORB POISONOUS MATERIALS FROM THE OIL THROUGH YOUR SKIN.
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