APU Control Panel Flashcards
1
Q
MAINT light
Blue
A
- low oil qty for the APU or starter-generator has a shorted rotating diode
- when the oil level is at LOQ, there is enough oil in the APU for 30 - 50 hours of operation at the max oil consumption rate
2
Q
LOW OIL PRESSURE light
A
- illuminated = oil press low
- auto shutdown occurs in 20 sec
- illuminates during start until oil pressure is normal
- if light is on when APU switch is placed to OFF, it extinguishes after 5 min
- light is disarmed when the APU switch is in OFF position
3
Q
FAULT light
A
- a malfunction exists which causes the APU to initiate an automatic shutdown
- shows that the APU ECU sensed a fault and a protective shutdown has occurred
- if light is on when APU switch is placed to OFF, it extinguishes after 5 min
4
Q
OVERSPEED light
A
- illuminates if actual overspeed (106%),
- auto shutdown and light stays on even with switch OFF
- if light is on when APU switch is placed to OFF, it extinguishes after 5 min
- maintenance must reset
5
Q
APU Start switch (3)
Switched to off it:
A
- starts cool-down cycle
- APU generator breaker trips and the APU bleed air valve closes
- APU continues to run for 60 sec then shuts down