DOC AIRBUS | AMM A320FIGNITION AND STARTING - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. General
The ignition and starting systems are necessary to start the APU. They operate electrically and are supplied from the aircraft electrical system.
The two aircraft batteries are used to supply power through the system to the starter motor. When external power or main-engine generator-power is used the batteries are assisted by the Transformer Rectifier Unit (TRU).
The two aircraft batteries are installed in the avionics compartment, below the cockpit. A cable passes electrical power to the starter motor.
This cable is routed through the aircraft, along the ceiling of the cabin. The APU has an inflight restart capability within an established altitude and airspeed envelope. The aircraft's batteries or the TRU rectified electrical power is used to start the APU in flight.
** ON A/C NOT FOR ALL The ignition and starting systems are necessary to start the APU. They operate electrically and are supplied from the aircraft electrical system.
The two aircraft batteries are used to supply power through the system to the starter motor. When external power or main-engine generator-power is used the batteries are assisted by the Transformer Rectifier Unit (TRU).
The two aircraft batteries are installed in the avionics compartment, below the cockpit. A cable passes electrical power to the starter motor.
This cable is routed through the aircraft, along the ceiling of the cabin. The APU has an inflight restart capability within an established altitude and airspeed envelope. The aircraft's batteries or the TRU rectified electrical power is used to start the APU in flight.
Ignition and Starting - Component LocationA. Ignition System
The ignition system gives the constant high-energy ignition which ignites the fuel/air mixture in the combustion chamber. It operates during the start sequence when the APU speed is between 7% and 60%. The Electronic Control Box (ECB) controls the ignition system fully automatically.
When the APU speed is below 88% the ECB energizes the ignition system to ensure a stable combustion.
The ignition system gives the constant high-energy ignition which ignites the fuel/air mixture in the combustion chamber. It operates during the start sequence when the APU speed is between 7% and 60%. The Electronic Control Box (ECB) controls the ignition system fully automatically.
The ECB energizes the ignition exciter when the APU speed decreases 2% below the speed set by the ECB.
The ignition system gives the constant high-energy ignition which ignites the fuel/air mixture in the combustion chamber. It operates during the start sequence when the APU speed is between 7% and 60%. The Electronic Control Box (ECB) controls the ignition system fully automatically.
When the APU speed is below 88% the ECB energizes the ignition system to ensure a stable combustion.
The ignition system gives the constant high-energy ignition which ignites the fuel/air mixture in the combustion chamber. It operates during the start sequence when the APU speed is between 7% and 60%. The Electronic Control Box (ECB) controls the ignition system fully automatically.
The ECB energizes the ignition exciter when the APU speed decreases 2% below the speed set by the ECB.
B. Starting System
The starting system rotates and accelerates the rotor of the APU to 50 % or in high altitude (P2 < 6.76PSIA) up to 58% of the APU's usual speed. You can operate the starting system from the APU panel in the cockpit. The Electronic Control Box (ECB) 59KD controls the start sequence of the APU. Three consecutive start attempts are permitted without cooldown. After the third start attempt the starter motor must cool down for at least 60 minutes.
The starting system rotates and accelerates the rotor of the APU to 50 % or in high altitude (P2 < 6.76PSIA) up to 58% of the APU's usual speed. You can operate the starting system from the APU panel in the cockpit. The Electronic Control Box (ECB) 59KD controls the start sequence of the APU. Three consecutive start attempts are permitted without cooldown. After the third start attempt the starter motor must cool down for at least 60 minutes.