DOC AIRBUS | AMM A320FEMERGENCY SHUTDOWN - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. General
The APU emergency shutdown-system stops the APU if an emergency occurs. The system is automatically activated on the ground if the APU fire and overheat detection system finds an overtemperature in the APU compartment (Ref. 26-13-00). You can also stop the APU manually from:
** ON A/C NOT FOR ALL The APU emergency shutdown-system stops the APU if an emergency occurs. The system is automatically activated on the ground if the APU fire and overheat detection system finds an overtemperature in the APU compartment (Ref. 26-13-00). You can also stop the APU manually from:
- the cockpit,
- the external power control panel on the nose landing gear (only when the aircraft is on the ground).
2. Component Location
** ON A/C NOT FOR ALL 
APU Emergency Shutdown - Component Location| FIN | FUNCTIONAL DESIGNATION | PANEL | ZONE | ACCESS DOOR | ATA REF |
|---|---|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||||
| 1KL | CTL SW-APU SHUT OFF | 108VU | 120 | 49-62-00 | |
3. System Description
The airborne auxilary power has an APU emergency shutdown-system. The Electronic Control Box (ECB) receives the emergency shutdown signal and stops the APU.
An emergency shutdown occurs automatically, if the APU fire and overheat detection system finds an overtemperature in the APU compartment (Ref. 26-13-00).
The manual emergency shutdown switches are:
During the flight you must push the APU AGENT pushbutton switch 10WF on the APU panel 20VU to operate the fire extinguishing system (Ref. AMM D/O 26-22-00-00).
** ON A/C NOT FOR ALL The airborne auxilary power has an APU emergency shutdown-system. The Electronic Control Box (ECB) receives the emergency shutdown signal and stops the APU.
An emergency shutdown occurs automatically, if the APU fire and overheat detection system finds an overtemperature in the APU compartment (Ref. 26-13-00).
The manual emergency shutdown switches are:
- the APU FIRE PUSH pushbutton switch 12WG on the overhead panel 20VU in the cockpit,
- the APU SHUT OFF pushbutton switch 1KL at the fuselage of the nose landing gear, on the external power control panel 108VU (this is only available when the aircraft is on the ground).
During the flight you must push the APU AGENT pushbutton switch 10WF on the APU panel 20VU to operate the fire extinguishing system (Ref. AMM D/O 26-22-00-00).
A. Automatic Emergency Shutdown
For the automatic emergency shutdown the ECB receives a shutdown signal from the fire emergency-stop relays 1 (5WF) and 2 (6WF) (Ref. AMM D/O 26-22-00-00). The ECB then starts the shutdown sequence.
For the automatic emergency shutdown the ECB receives a shutdown signal from the fire emergency-stop relays 1 (5WF) and 2 (6WF) (Ref. AMM D/O 26-22-00-00). The ECB then starts the shutdown sequence.
B. Manual Emergency Shutdown
For the manual emergency shutdown the ECB receives a shutdown signal from:
For the manual emergency shutdown the ECB receives a shutdown signal from:
- the APU FIRE PUSH pushbutton switch 12WG on the overhead panel 20VU,
- the APU SHUT OFF pushbutton switch 1KL at the fuselage of the nose landing gear, on the external power control panel 108VU.
C. APU Shutdown Sequence
If the ECB receives the emergency shutdown signal during the operation of the APU, it stops the APU immediately without a cooldown cycle.
If the ECB receives the emergency shutdown signal during the cooldown cycle of a shutdown, it stops the APU also immediately.
The shutdown sequence is the same than an APU automatic shutdown without a cooldown cycle (Ref. AMM D/O 49-61-00-00).
If the ECB receives the emergency shutdown signal during the operation of the APU, it stops the APU immediately without a cooldown cycle.
If the ECB receives the emergency shutdown signal during the cooldown cycle of a shutdown, it stops the APU also immediately.
The shutdown sequence is the same than an APU automatic shutdown without a cooldown cycle (Ref. AMM D/O 49-61-00-00).
D. Indications
When an emergency shutdown of the APU occurs, the upper ECAM display unit shows the warning:
APU
EMER SHUT DOWN
MASTER SW ....................OFF
When an emergency shutdown of the APU occurs, the upper ECAM display unit shows the warning:
APU
EMER SHUT DOWN
MASTER SW ....................OFF