W DOC AIRBUS | AMM A320F

To make sure that the APU Automatic Fire Extinguishing System is operative when the APU SHUT OFF PB on External Power Panel is inoperative


TASK 26-22-00-040-011-A
To make sure that the APU Automatic Fire Extinguishing System is operative when the APU SHUT OFF PB on External Power Panel is inoperative


Task Summary
Access Test Specific Tools Mhr E/T Nb Men
NONONO0.30.31
1. Reason for the Job
MMEL 26-22-07A
APU SHUT OFF ON THE EXTERNAL POWER PANEL
2. Job Set-up Information
 A. Fixtures, Tools, Test and Support Equipment
REFERENCE
QTY
DESIGNATION
No specific
1
WARNING NOTICE(S)
 B. Referenced Information
REFERENCE
DESIGNATION
TASK 24-41-00-861-002-A
Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-02
Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A
De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-02
De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
3. Job Set-up
Subtask 26-22-00-941-064-A
A. Put the WARNING NOTICE(S) in position on the overhead panel 25VU to tell persons not to operate the APU.
Subtask 26-22-00-860-070-A
B. Aircraft Maintenance Configuration
   (1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002) or (Ref. AMM TASK 24-41-00-861-002).
4. Procedure
Subtask 26-22-00-710-075-A ** ON A/C NOT FOR ALL
WARNING: DO NOT PUSH THE TEST PUSHBUTTON SWITCH ON THE APU/AUTO EXTING SECTION OF OVERHEAD PANEL 50VU WHILE THE APU IS IN OPERATION. IF YOU DO, DISCHARGE OF THE APU-FIRE EXTINGUISHER BOTTLE CAN OCCUR.
A. Operational Test of the Test Circuit
ACTION
RESULT
1.In the APU/AUTO EXTING section of panel 50VU:
  • Push the TEST ON pushbutton during the test.
In the APU/AUTO EXTING section of panel 50VU:
  • The OK legend in the TEST pushbutton switch comes on.
NOTE: If the OK legend in the TEST pushbutton switch comes on, all components operate correctly.
2.In the APU/AUTO EXTING section of panel 50VU:
  • Push the RESET pushbutton switch.
In the APU/AUTO EXTING section of panel 50VU:
  • The test circuit sets back.
Subtask 26-22-00-710-075-B ** ON A/C NOT FOR ALL
WARNING: DO NOT PUSH THE TEST PUSHBUTTON SWITCH ON THE APU/AUTO EXTING SECTION OF OVERHEAD PANEL 50VU WHILE THE APU IS IN OPERATION. IF YOU DO, DISCHARGE OF THE APU-FIRE EXTINGUISHER BOTTLE CAN OCCUR.
A. Operational Test of the Test Circuit
NOTE: This test causes a spurious WARNING in ECAM (APU FIRE LOOP A FAULT) because of a FDU hardware modification.
ACTION
RESULT
1.In the APU/AUTO EXTING section of panel 50VU:
  • Push the TEST ON pushbutton during the test.
In the APU/AUTO EXTING section of panel 50VU:
  • The OK legend in the TEST pushbutton switch comes on.

After 5 seconds, on the ECAM upper display unit:
  • The warning,
    APU FIRE LOOP A FAULT
    comes on.
NOTE: If the OK legend in the TEST pushbutton switch comes on, all components operate correctly.
2.In the APU/AUTO EXTING section of panel 50VU:
  • Push the RESET pushbutton switch.
In the APU/AUTO EXTING section of panel 50VU:
  • The test circuit sets back.
5. Close-up
Subtask 26-22-00-410-067-A
A. Put the aircraft back to its initial configuration.
   (1) Make an entry in the aircraft technical logbook.
Subtask 26-22-00-860-071-A
B. Put the aircraft back to its initial configuration.
   (1) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002) or (Ref. AMM TASK 24-41-00-862-002).
[Rev.10 from 2021] 2026.03.31 23:45:28 UTC