W DOC AIRBUS | TSM A320F

Failure of the AEVC Power Supplies or Inadvertent Pressure Switch Detection

TASK 21-26-00-810-841-A
Failure of the AEVC Power Supplies or Inadvertent Pressure Switch Detection

1. Possible Causes
  • P/BSW-VENTILATION/BLOWER (13HQ)
  • wiring
  • C/B-AIR COND/AVNCS VENT/CTL [5HQ]
  • C/B-AIR COND/AVNCS VENT/CTL [6HQ]
  • P/BSW-VENTILATION/EXTRACT (14HQ)
  • P/BSW-CABIN PRESS/DITCHING (13HL)
  • AEVC [10HQ]
  • PRESS SW-BLOWER FAN, AVNCS VENT [17HQ]
  • PRESS SW-BLOWER FAN, AVNCS VENT [19HQ]
  • SENSOR-DUCT TEMP, AVNCS VENT [26HQ]
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
TSM TASK 24-00-00-810-803-A
Circuit Breaker Tripped and/or C/B TRIPPED Warning
AMM 21-26-00-710-001
Operational Check of the Avionics Equipment Ventilation-System via MCDU
AMM 21-26-00-710-008
Operational Test to Read the CFDS for CLASS 3 Faults of the AEVC
AMM 21-26-00-710-009
Operational Test to Read the CFDS for LAST LEG REPORT of the AEVC
ASM 212602
ASM 212603
AMM 21-26-11-000-001
Removal of the Blower and Extract Fan Pressure Switches
AMM 21-26-11-400-001
Installation of the Blower and Extract Fan Pressure Switches
AMM 21-26-12-000-001
Removal of the Avionics Ventilation Duct Temperature Sensor
AMM 21-26-12-400-001
Installation of the Avionics Ventilation Duct Temperature Sensor
AMM 21-26-34-000-001
Removal of the Avionics Equipment Ventilation Computer (AEVC)
AMM 21-26-34-400-001
Installation of the Avionics Equipment Ventilation Computer (AEVC)
3. Fault Confirmation
Subtask 21-26-00-865-078-A
A. Table of the circuit breakers used in this procedure:
PANELDESIGNATIONFINLOCATION
** ON A/C ALL
49VUAIR COND/AVNCS VENT/CTL6HQD06
49VUAIR COND/AVNCS VENT/CTL5HQD05
122VUAIR COND/AVNCS/VENT/MONG3HQY17
Subtask 21-26-00-710-121-A
B. Test
   (1) Do the reset of the AEVC (10HQ).
     (a) Open the circuit breaker AIR COND/AVNCS/VENT/MONG (3HQ).
     (b) Wait for five seconds.
     (c) Close the circuit breaker AIR COND/AVNCS/VENT/MONG (3HQ).
   (2) Do the operational test of the avionics equipment ventilation from the Multipurpose Control and Display Unit (MCDU) AMM 21-26-00-710-001.
   (3) Read the LAST LEG REPORT of the AEVC AMM 21-26-00-710-009.
   (4) Read the CLASS 3 faults of the AEVC AMM 21-26-00-710-008.
4. Fault Isolation
Subtask 21-26-00-810-098-A
A. If the test gives the maintenance message CHECK AEVC SUPPLY:
  • Do a check of the status of the AIR COND/AVNCS VENT/CTL circuit breaker (5HQ).
   (1) If the AIR COND/AVNCS VENT/CTL circuit breaker (5HQ) is closed:
  • Make sure that the VENTILATION/BLOWER pushbutton switch (13HQ) is pushed.
  • Do a check for 28VDC at pin AA/7C and pin AA/1B of the AEVC (10HQ) ASM 212603 and ASM 212602
     (a) If there is no 28VDC at pin AA/7C:
  • Do a check for 28VDC at pin A/D3 of the VENTILATION/BLOWER pushbutton switch (13HQ) ASM 212603.
       1 If there is 28VDC:
  • Replace the P/BSW-VENTILATION/BLOWER (13HQ).
       2 If there is no 28VDC:
  • Do a check of the wiring ASM 212603 between:
    . Pin AA/7C of the AEVC (10HQ) and pin A/D1 of the VENTILLATION/BLOWER pushbutton switch (13HQ)
    . Pin A/D3 of the VENTILLATION/BLOWER pushbutton switch (13HQ) and pin 2 of the AIR COND/AVNCS VENT/CTL circuit breaker (5HQ).
         a If there is no continuity:
  • Repair the related wiring .
         b If there is continuity:
  • Replace the C/B-AIR COND/AVNCS VENT/CTL [5HQ] .
     (b) If there is no 28VDC at pin AA/1B:
  • Do a check of the wiring between pin AA/1B of the AEVC (10HQ) and pin 2 of the AIR COND/AVNCS VENT/CTL circuit breaker (5HQ) ASM 212602.
       1 If there is no continuity:
  • Repair the related wiring .
       2 If there is continuity:
  • Replace the C/B-AIR COND/AVNCS VENT/CTL [5HQ] .
     (c) If there is 28VDC at pins AA/7C and AA/1B:
  • Do a check of the status of the AIR COND/AVNCS VENT/CTL circuit breaker (6HQ).
       1 If the AIR COND/AVNCS VENT/CTL circuit breaker (6HQ) is closed:
  • Make sure that the VENTILATION/EXTRACT pushbutton switch (14HQ) is pushed.
  • Make sure that the CABIN PRESS/DITCHING pushbutton switch (13HL) is released.
  • Do a check for 28VDC at pin AA/1C ASM 212603, at pin AA/2C and pin AA/3D ASM 212602 of the AEVC (10HQ).
         a If there is no 28VDC at pin AA/1C:
  • Do a check of the wiring between pin AA/1C of the AEVC (10HQ) and pin 2 of the AIR COND/AVNCS VENT/CTL circuit breaker (6HQ) ASM 212603.

    * If there is no continuity:
    * - Repair the related wiring.

    * If there is continuity:
    * - Replace the C/B-AIR COND/AVNCS VENT/CTL [6HQ] .
         b If there is no 28VDC at pin AA/2C:
  • Do a check for 28VDC at pin A/D3 of the VENTILATION/EXTRACT pushbutton switch (14HQ) ASM 212602.

    * If there is 28VDC:
    * - Replace the P/BSW-VENTILATION/EXTRACT (14HQ).

    * If there is no 28VDC:
    * - Do a check of the wiring ASM 212602 between:
    * . Pin AA/2C of the AEVC (10HQ) and pin A/D1 of the VENTILATION/EXTRACT pushbutton switch (14HQ)
    * . Pin A/D3 of the VENTILATION/EXTRACT pushbutton switch (14HQ) and pin 2 of the AIR COND/AVNCS VENT/CTL circuit breaker (6HQ).

    ** If there is no continuity:
    ** - Repair the related wiring .

    ** If there is continuity:
    ** - Replace the C/B-AIR COND/AVNCS VENT/CTL [6HQ] .
         c If there is no 28VDC at pin AA/3D:
  • Release the VENTILATION/EXTRACT pushbutton switch (14HQ).
  • Do a check for 28VDC at pin A/C3 of the VENTILATION/BLOWER pushbutton switch (13HQ) ASM 212602.

    * If there is 28VDC:
    * - Replace the P/BSW-VENTILATION/BLOWER (13HQ).

    * If there is no 28VDC:
    * - Do a check of the wiring ASM 212602 between:
    * . Pin AA/3D of the AEVC (10HQ) and pin A/C1 of the VENTILATION/BLOWER pushbutton switch (13HQ)
    * . Pin A/C3 of the VENTILATION/BLOWER pushbutton switch (13HQ) and pin A/C2 of the VENTILATION/EXTRACT pushbutton switch (14HQ)
    * . Pin A/C1 of the VENTILATION/EXTRACT pushbutton switch (14HQ) and pin AA/3D of the AEVC (10HQ).

    ** If there is no continuity:
    ** - Repair the related wiring .

    ** If there is continuity:
    ** - Do a check for 28VDC at pin A/C3 of the VENTILATION/EXTRACT pushbutton switch (14HQ) ASM 212602.

    *** If there is 28VDC:
    *** - Replace the P/BSW-VENTILATION/EXTRACT (14HQ).

    *** If there is no 28VDC:
    *** - Do a check of the wiring between pin A/C3 of the VENTILATION/EXTRACT pushbutton switch (14HQ) and pin A/C2 of the CABIN PRESS/DITCHING pushbutton switch (13HL) ASM 212602.

    **** If there is no continuity:
    **** - Repair the related wiring .

    **** If there is continuity:
    **** - Do a check for 28VDC at pin A/C3 of the CABIN PRESS/DITCHING pushbutton switch (13HL) ASM 212602.

    ***** If there is 28VDC:
    ***** - Replace the P/BSW-CABIN PRESS/DITCHING (13HL).

    ***** If there is no 28VDC:
    ***** - Do a check of the wiring between pin A/C3 of the CABIN PRESS/DITCHING pushbutton switch (13HL) and pin 2 of the AIR COND/AVNCS VENT/CTL circuit breaker (6HQ) ASM 212602.

    ****** If there is no continuity:
    ****** - Repair the related wiring.

    ****** If there is continuity:
    ****** - Replace the C/B-AIR COND/AVNCS VENT/CTL [6HQ] .
         d If there is 28VDC at pin AA/1C, pin AA/2C and pin AA/3D:
  • Do a check for a ground signal at pin AA/1D of the AEVC (10HQ) ASM 212603.

    * If there is a ground signal:
    * - Replace the AEVC [10HQ] AMM 21-26-34-000-001 and AMM 21-26-34-400-001.

    * If there is no ground signal:
    * - Repair the wiring between the AEVC pin AA/1D and the ground terminal.
       2 If the AIR COND/AVNCS VENT/CTL circuit breaker (6HQ) is open:
         a If the fault continues:
  • Replace the C/B-AIR COND/AVNCS VENT/CTL [6HQ] .
         b If the fault continues:
   (2) If the AIR COND/AVNCS VENT/CTL circuit breaker (5HQ) is open:
     (a) If the fault continues:
  • Replace the C/B-AIR COND/AVNCS VENT/CTL [5HQ] .
     (b) If the fault continues:
   (3) If the fault continues:
  • Do a check of the wiring ASM 212603 between:
    . Pin AB/8C of the AEVC (10HQ) and pin A/A of the blower fan pressure-switch (17HQ)
    . Pin A/C of the blower fan pressure-switch (17HQ) and the ground.
     (a) If the wiring is not correct:
  • Repair the wiring .
     (b) If the wiring is correct:
   (4) If the fault continues:
  • Do a check of the wiring ASM 212603 between:
    . Pin AB/8D of the AEVC (10HQ) and pin A/A of the blower fan pressure-switch (19HQ)
    . Pin A/C of the blower fan pressure-switch (19HQ) and the ground.
     (a) If the wiring is not correct:
  • Repair the wiring .
     (b) If the wiring is correct:
   (5) If the fault continues:
  • Do a check of the wiring ASM 212603 between:
    . Pin AB/5D of the AEVC (10HQ) and pin A/C of the duct temperature sensor (26HQ)
    . Pin A/B of the duct temperature sensor (26HQ) and the ground.
     (a) If the wiring is not correct:
  • Repair the wiring .
     (b) If the wiring is correct:
Subtask 21-26-00-710-122-A
B. Do the test given in Para. 3.
[Rev.8 from Aug 2018] 2026.04.04 04:24:39 UTC
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