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 assisted by the Transformer Rectifier Unit (TRU) if powered through the external power or if the main engine generator supplies sufficient power to start the APU.
The two aircraft batteries are installed in the avionics compartment, below the cockpit. A starter cable supplies electrical current 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. In this case, the aircraft's batteries or the TRUs rectifier supply electrical power to the starter motor.
** 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.
Ignition and Starting - ComponentsThe two aircraft batteries are assisted by the Transformer Rectifier Unit (TRU) if powered through the external power or if the main engine generator supplies sufficient power to start the APU.
The two aircraft batteries are installed in the avionics compartment, below the cockpit. A starter cable supplies electrical current 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. In this case, the aircraft's batteries or the TRUs rectifier supply electrical power to the starter motor.
2. System Description
A. Ignition System
The ignition system is a dual system with two igniter plugs, which 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 below 55%. The Electronic Control Box (ECB) controls the ignition system fully automatically.
The ignition system is a dual system with two igniter plugs, which 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 below 55%. The Electronic Control Box (ECB) controls the ignition system fully automatically.
B. Starting System
The starting system rotates and accelerates the rotor of the APU to 55% 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 55% 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.