A320-A330 APU PDF

GENERAL APU MASTER SW GENERAL APU MASTER SW Ø On groun...

GENERAL APU MASTER SW GENERAL APU MASTER SW Ø On ground: Ø On ground: Ø ON/R: Ø ON/R: Supplies bleed air for ENG start and Air Conditioning. Supplies bleed air for ENG start and Air APU Powered & ECB performs APU Powered & ECB performs Supplies Electrical power. Conditioning. power up test. power up test. Ø During TO: Can supply bleed air for Air Conditioning. Supplies Electrical power. Intake flap, fuel isol valve & LP Intake flap, fuel isol valve opens. Ø In flight: Ø During TO: Can supply bleed air for Air valve opens. If no fuel pump is operating, APU Backs up electrical system. Conditioning. FWD, AFT APU fuel pumps fuel pump operates. Backs up Air conditioning system. Ø In flight: operate during TT fuel XFR and Ø OFF: Can be used to start the engines. Backs up electrical system. depending on TT line pressure. APU shuts down. If bleed was Ø Can be started by APU BAT or EXT PWR or aircraft Backs up Air conditioning system. Ø OFF: used cooling period of 60-120sec. normal supply. Can be used to start the engines. After 15 sec(for NBPT), APU shuts At 7%N inlet flap closes. Ø BAT start limit is 25,000ft. Ø Can be started by BATs or EXT PWR or aircraft down. If bleed was used cooling APU START PB Ø Air intake system: Electrically operated flap. normal supply. period at 82% speed for 85sec. Ø When flap fully open, starter Ø Starter: Engages if the air intake is fully open and Ø BAT start limit is 25,000ft. At 7%N inlet flap closes. energised. provided the MASTER SW and the START PB are on. Ø Air intake system: Electrically operated flap. Recycling the MASTER SW resets Ø 1.5sec after starter energised: IGN Ø Oil System: APU has an integral, independent Ø Starter: Engages if the air intake is fully open and ECB. ON. lubrication system which is also used for cooling. provided the MASTER SW and the START PB are APU START PB Ø At 60%N: IGN OFF, Ø IGVs: controls bleed and a fuel pressure powered on. Ø When flap fully open, starter Starter de energised. actuator controlled by the ECB positions the IGVs. Ø Oil System: APU has an integral, independent energised. Ø At 95%N: AVAIL Ø If APU BLEED SW is ON, valve closes at 25,000ft when lubrication system which is also used for cooling. Ø At 7%N: IGN ON. Ø IGVs: controls bleed and a fuel pressure Ø At 50%N: IGN OFF, climbing and reopens at 23,000ft when descending. powered actuator controlled by the ECB Starter de energised. Electronic Control Box: positions the IGVs. Ø ECB is a FADEC that performs the APU system logic for Ø At 95%N: AVAIL Electronic Control Box: all modes of APU operations such as: Ø ECB is a FADEC that performs the APU system Sequence the start and monitors. logic for all modes of APU operations such as: Monitors the speed and temperature. Sequence the start and monitors. Monitors the bleed air(IGV). Monitors the speed and temperature. Sequences the shutdown(manual, protective or Monitors the bleed air. inhibited). APU AUTO SHUTDOWN APU AUTO SHUTDOWN Fuel System: Sequences the manual or auto shutdown. Fuel System: Ø On ground, if there is a fire, APU Ø On ground, if there is a fire, APU Ø Supplied through the trim tank transfer line and the Ø Left fuel feed line supplies the APU. auto shuts down and fire auto shuts down and fire ECB controls the fuel flow. Ø Required pressure is normally available from extinguisher discharges. External extinguisher discharges. External Ø APU feed line is pressurised if the APU MAST SW is ON. tank pumps. horn sounds. horn sounds. Ø If initial start attempt fails, wait 3 minutes before Ø When EGT> RED EGT LIM, APU auto Ø On ground, in most cases of APU setting APU START PB ON again to ensure APU fuel feed Ø If unavailable(BATs OFF or PUMPs OFF), APU Fuel pump auto starts. shuts down. auto shutdown, NBPT is inhibited. line is sufficiently pressurised. Ø ECB controls the fuel flow. Ø Overspeed and certain critical ECB internal failures leads to an auto shutdown in all flight phases. Ø Auto shutdown is inhibited for all other failures from flight phase 2 to 9. Ø When EGT> RED EGT LIM, APU auto shuts down. 49: APU : A320 49: APU : A330