DOC AIRBUS | TSM A320FWarning of the Blower-Fan Pressure Switch Inoperative
TASK 21-26-00-810-815-A
Warning of the Blower-Fan Pressure Switch Inoperative
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
3. Fault Confirmation
Subtask 21-26-00-865-070-A
Subtask 21-26-00-810-053-A
[Rev.8 from Aug 2018]
2026.04.04 04:24:37 UTC
Warning of the Blower-Fan Pressure Switch Inoperative
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| 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 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 21-26-34-000-001 | Removal of the Avionics Equipment Ventilation Computer (AEVC) |
| AMM 21-26-34-400-001 | Installation of the Avionics Equipment Ventilation Computer (AEVC) |
Subtask 21-26-00-865-070-A
A. Table of the circuit breakers used in this procedure:
Subtask 21-26-00-710-056-A | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C ALL | |||
| 122VU | AIR COND/AVNCS/VENT/MONG | 3HQ | Y17 |
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(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.
Subtask 21-26-00-810-053-A
A. If the test gives the maintenance message PRESSURE SW 17HQ:
Subtask 21-26-00-710-057-A - Replace the PRESS SW-BLOWER FAN, AVNCS VENT [17HQ] AMM 21-26-11-000-001 and AMM 21-26-11-400-001.
- Replace the AEVC [10HQ] AMM 21-26-34-000-001 and AMM 21-26-34-400-001.
- Do a check and repair 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.
B. Do the operational test given in Para. 3.