DOC AIRBUS | TSM A320FPack 2 Overheat
TASK 21-61-00-810-802-A
Pack 2 Overheat
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 21-61-00-710-152-A
Subtask 21-61-00-810-063-A
Subtask 21-61-00-860-051-A
[Rev.8 from Aug 2018]
2026.04.04 04:38:53 UTC
Pack 2 Overheat
1. Possible Causes
- P2 FLOW CTL VALVE [8HB]
- SENSOR-COMPRESSOR TEMPERATURE [32HH]
- SENSOR-COMPRESSOR OVHT [35HH]
- RELAY-WHEEL 3 SPEED [24GG]
- BSCU [10GG]
- P2 CONTROLLER [27HH]
- P2 FLOW SENSOR [9HB]
- FLOW CTL UNIT - PACK 2 [24HB]
- CONT-AIR COND SYSTEM 2 [57HH]
- SENSOR-DELTA P, PACK 2 [24HB2]
- MACHINE-AIR CYCLE [11HM1]
- SENSOR-PACK OUTLET TEMP [34HH]
- water injector nozzle
- HEAT EXCHANGER-MAIN [11HM7]
- HEAT EXCHANGER-PRIMARY [11HM6]
- CONDENSER [11HM2]
- condensor leakage
- REHEATER [11HM3]
- PLENUM CHAMBER [11HM5]
- VALVE-ANTI ICE [37HH]
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| AMM 12-33-21-618-001 | Pre-conditioning through the LP Ground Connection |
| AMM 21-51-11-000-001 | Removal of the Differential Pressure Sensor |
| AMM 21-51-11-400-001 | Installation of the Differential Pressure Sensor |
| AMM 21-51-51-000-001 | Removal of the Pack Flow-Control Valve/ Pack Flow-Control Unit |
| AMM 21-51-51-400-001 | Installation of the Pack Flow-Control Valve/ Pack Flow-Control Unit |
| AMM 21-52-00-100-001 | Cleaning of the Air Conditioning Pack-Primary Heat Exchanger and the Main Heat Exchanger |
| AMM 21-52-00-100-002 | Remove Reheater for Cleaning |
| AMM 21-52-00-100-003 | Cleaning of the Air Conditioning Pack-Condenser |
| AMM 21-52-00-200-001 | Detailed Inspection of the Plenum Chamber for Signs of Delamination |
| AMM 21-52-00-200-003 | Detailed Visual Inspection of the Anti-Ice Valve Sense-Lines |
| AMM 21-52-00-780-001 | Pressure Drop Test of the Reheater |
| AMM 21-52-00-790-001 | Remove Condenser for Leak Test |
| AMM 21-52-00-960-001 | Replacement of the Water Injector Nozzle |
| AMM 21-52-21-000-001 | Removal of the Air Cycle Machine |
| AMM 21-52-21-400-001 | Installation of the Air Cycle Machine |
| AMM 21-52-22-000-001 | Removal of the Fan Plenum Chamber |
| AMM 21-52-22-400-001 | Installation of the Fan Plenum Chamber |
| AMM 21-61-00-710-001 | Operational Test of the Pack Temperature-Control System |
| ASM 216101 | |
| ASM 216102 | |
| AMM 21-61-11-000-001 | Removal of the Compressor Outlet - Temperature Sensor |
| AMM 21-61-11-400-001 | Installation of the Compressor Outlet - Temperature Sensor |
| AMM 21-61-12-000-001 | Removal of the Compressor Overheat - Temperature Sensor |
| AMM 21-61-12-400-001 | Installation of the Compressor Overheat - Temperature Sensor |
| AMM 21-61-15-000-001 | Removal of the Pack Outlet - Temperature Sensors |
| AMM 21-61-15-400-001 | Installation of the Pack Outlet - Temperature Sensors |
| AMM 21-61-34-000-001 | Removal of the Pack Controller |
| AMM 21-61-34-000-002 | Removal of the Air-Conditioning System Controller |
| AMM 21-61-34-400-001 | Installation of the Pack Controller |
| AMM 21-61-34-400-002 | Installation of the Air-Conditioning System Controller |
| AMM 21-61-41-000-001 | Removal of the Anti-Ice Valve |
| AMM 21-61-41-400-001 | Installation of the Anti-Ice Valve |
| AMM 32-42-34-400-001 | Installation of the Braking/Steering Control Unit (BSCU) |
Subtask 21-61-00-710-152-A
A. APU Bleed-Air Pressure Check
(1) Do the pre-conditioning with the APU AMM 12-33-21-618-001.
(2) Make sure that the APU bleed-air pressure is higher than 12 psi (0.8274 bar).
(3) Stop the pre-conditioning with the APU AMM 12-33-21-618-001.
(4) If the APU bleed-air pressure is lower than or equal to 12 psi (0.8274 bar), do the trouble shooting of the APU (refer to the fault symptom list / 49-OBSV, APU BLEED FAULT No, Low or Fluctuating APU Bleed-Air Pressure) before you continue with the subsequent procedure.
Subtask 21-61-00-710-052-A ** ON A/C NOT FOR ALL (1) Do the pre-conditioning with the APU AMM 12-33-21-618-001.
(2) Make sure that the APU bleed-air pressure is higher than 12 psi (0.8274 bar).
(3) Stop the pre-conditioning with the APU AMM 12-33-21-618-001.
(4) If the APU bleed-air pressure is lower than or equal to 12 psi (0.8274 bar), do the trouble shooting of the APU (refer to the fault symptom list / 49-OBSV, APU BLEED FAULT No, Low or Fluctuating APU Bleed-Air Pressure) before you continue with the subsequent procedure.
B. Test
(1) Do the operational test of the pack temperature-control system AMM 21-61-00-710-001.
(3) Do a check that the pack 2 inlet-pressure indication on the ECAM BLEED page is > 20 PSI.
(4) Do a check of the pack 2 flow indicator, the compressor discharge and pack outlet temperature on the ECAM BLEED page.
(5) Do a check to see that there is airflow at the pack 2 ram-air outlet.
Subtask 21-61-00-710-052-B ** ON A/C NOT FOR ALL (1) Do the operational test of the pack temperature-control system AMM 21-61-00-710-001.
NOTE: If a fault is detected, the PC gives a fault code for shop maintenance in addition to the related CFDS message(s) (refer to TSM chapter 21-63-00, page block 301).
(2) Do the pre-conditioning through the HP ground connection AMM 12-33-21-618-001. (3) Do a check that the pack 2 inlet-pressure indication on the ECAM BLEED page is > 20 PSI.
(4) Do a check of the pack 2 flow indicator, the compressor discharge and pack outlet temperature on the ECAM BLEED page.
(5) Do a check to see that there is airflow at the pack 2 ram-air outlet.
B. Test
(1) Do the operational test of the pack temperature-control system AMM 21-61-00-710-001.
(2) Do the pre-conditioning through the HP ground connection AMM 12-33-21-618-001.
(3) Do a check that the pack 2 inlet-pressure indication on the ECAM BLEED page is > 20 PSI.
(4) Do a check of the pack 2 flow indicator, the compressor discharge and pack outlet temperature on the ECAM BLEED page.
(5) Do a check to see that there is airflow at the pack 2 ram-air outlet.
4. Fault Isolation(1) Do the operational test of the pack temperature-control system AMM 21-61-00-710-001.
(2) Do the pre-conditioning through the HP ground connection AMM 12-33-21-618-001.
(3) Do a check that the pack 2 inlet-pressure indication on the ECAM BLEED page is > 20 PSI.
(4) Do a check of the pack 2 flow indicator, the compressor discharge and pack outlet temperature on the ECAM BLEED page.
(5) Do a check to see that there is airflow at the pack 2 ram-air outlet.
Subtask 21-61-00-810-063-A
A. If the pack 2 inlet-pressure indication on the ECAM BLEED page is < 20 PSI:
Subtask 21-61-00-810-064-A ** ON A/C NOT FOR ALL - increase the pressure to > 25 PSI.
B. For a Compressor Discharge Overheat Condition:
(1) If you select on the panel 30VU low airflow and the pack 2 flow indicator on the ECAM BLEED page moves to the HI indication:
(a) If the resistance values are out of the specified limits:
(a) If the resistance values are out of the specified limits:
(c) If the fault continues:
Subtask 21-61-00-810-053-A ** ON A/C NOT FOR ALL (1) If you select on the panel 30VU low airflow and the pack 2 flow indicator on the ECAM BLEED page moves to the HI indication:
- replace the P2 FLOW CTL VALVE [8HB] AMM 21-51-51-000-001 and AMM 21-51-51-400-001.
- do a check that the resistance of the compressor temperature sensor (32HH) measured between connector A/A and A/B is in these limits ASM 216102:
| Temp (Deg.C) | OHMS |
|---|---|
| + 10 | 103.9 +/- 0.5 |
| + 20 | 107.8 +/- 0.5 |
| + 30 | 111.7 +/- 0.5 |
| + 50 | 119.4 +/- 0.5 |
| + 70 | 127.1 +/- 0.5 |
| + 100 | 138.5 +/- 0.5 |
- replace the SENSOR-COMPRESSOR TEMPERATURE [32HH] AMM 21-61-11-000-001 and AMM 21-61-11-400-001.
- do a check that the resistance of the compressor overheat sensor (35HH) measured between connector A/A and A/B is in these limits ASM 216102:
| Temp (Deg.C) | OHMS |
|---|---|
| + 10 | 103.9 +/- 0.5 |
| + 20 | 107.8 +/- 0.5 |
| + 30 | 111.7 +/- 0.5 |
| + 50 | 119.4 +/- 0.5 |
| + 70 | 127.1 +/- 0.5 |
| + 100 | 138.5 +/- 0.5 |
- replace the SENSOR-COMPRESSOR OVHT [35HH] AMM 21-61-12-000-001 and AMM 21-61-12-400-001.
- do a check that the pack 2 ram-air inlet-flap is in the open position.
- do a check for a ground signal at the pack controller 2 (27HH) connector AA/10A ASM 216101.
- do a check of the RELAY-WHEEL 3 SPEED [24GG] and replace it if necessary ASM 216101.
- do the test for the BSCU [10GG] as given in the AMM TASK 32-42-34-400-001 para. 5.A AMM 32-42-34-400-001.
(c) If the fault continues:
- replace the P2 CONTROLLER [27HH] AMM 21-61-34-000-001 and AMM 21-61-34-400-001.
- replace the P2 FLOW SENSOR [9HB] AMM 21-51-11-000-001 and AMM 21-51-11-400-001.
C. For a Pack Outlet Overheat Condition
(1) If there is no airflow at the pack 2 ram-air outlet:
(a) If the resistance values are out of the specified limits:
(a) Remove the inspection panel from the pack 2 ram-air inlet plenum (11HM14),
(b) Do a check of the water injector nozzle for damage or wear:
(4) If the fault continues:
(a) Do a visual inspection of the plenum chamber of the air cycle machine AMM 21-52-00-200-001.
(b) If the plenum chamber is damaged:
(a) Replace the VALVE-ANTI ICE [37HH] AMM 21-61-41-000-001 and AMM 21-61-41-400-001.
(10) If the fault continues:
Subtask 21-61-00-810-064-B ** ON A/C NOT FOR ALL (1) If there is no airflow at the pack 2 ram-air outlet:
- replace the MACHINE-AIR CYCLE [11HM1] AMM 21-52-21-000-001 and AMM 21-52-21-400-001.
- do a check that the resistance of the pack outlet temperature sensor (34HH) measured between connector A/A and A/B is in these limits ASM 216102:
| Temp (Deg.C) | OHMS |
|---|---|
| + 10 | 103.9 +/- 0.5 |
| + 20 | 107.8 +/- 0.5 |
| + 30 | 111.7 +/- 0.5 |
| + 50 | 119.4 +/- 0.5 |
| + 70 | 127.1 +/- 0.5 |
| + 100 | 138.5 +/- 0.5 |
- replace the SENSOR-PACK OUTLET TEMP [34HH] AMM 21-61-15-000-001 and AMM 21-61-15-400-001.
(a) Remove the inspection panel from the pack 2 ram-air inlet plenum (11HM14),
(b) Do a check of the water injector nozzle for damage or wear:
- if the water injector nozzle is worn or damaged replace it AMM 21-52-00-960-001.
- if the main heat exchanger is clogged do the cleaning of the HEAT EXCHANGER-MAIN [11HM7] and the HEAT EXCHANGER-PRIMARY [11HM6] AMM 21-52-00-100-001.
(4) If the fault continues:
- do the cleaning of the clogged CONDENSER [11HM2] AMM 21-52-00-100-003,
- do the leak test of the condensor leakage AMM 21-52-00-790-001,
- do a check of the reheater (11HM3) for contamination AMM 21-52-00-780-001.
NOTE: This sub-paragraph (4) is only applicable to reheaters with the P/N 755A0000-04 and previous.
It is not applicable to reheaters with the P/N's 755A0000-04 Amendment A or subsequent.
(a) If the reheater is clogged: It is not applicable to reheaters with the P/N's 755A0000-04 Amendment A or subsequent.
- do the cleaning of the REHEATER [11HM3] AMM 21-52-00-100-002,
- replace the P2 CONTROLLER [27HH] AMM 21-61-34-000-001 and AMM 21-61-34-400-001.
(a) Do a visual inspection of the plenum chamber of the air cycle machine AMM 21-52-00-200-001.
(b) If the plenum chamber is damaged:
- replace the PLENUM CHAMBER [11HM5] AMM 21-52-22-000-001 and AMM 21-52-22-400-001.
- replace the P2 FLOW SENSOR [9HB] AMM 21-51-11-000-001 and AMM 21-51-11-400-001.
(a) Replace the VALVE-ANTI ICE [37HH] AMM 21-61-41-000-001 and AMM 21-61-41-400-001.
(10) If the fault continues:
- do a leakage check of the anti-ice valve sense-lines AMM 21-52-00-200-003, and remove if necessary.
D. For a Compressor Discharge Overheat Condition:
(1) If you select on the panel 30VU NORM airflow and the pack 2 flow indicator on the ECAM BLEED page moves to the HI indication:
(a) If the resistance values are out of the specified limits:
(c) If the fault continues:
Subtask 21-61-00-810-053-C ** ON A/C NOT FOR ALL (1) If you select on the panel 30VU NORM airflow and the pack 2 flow indicator on the ECAM BLEED page moves to the HI indication:
- replace the FLOW CTL UNIT - PACK 2 [24HB] AMM 21-51-51-000-001 and AMM 21-51-51-400-001.
- do a check that the resistance of the compressor discharge sensor (32HH) measured between connector A/B and A/C and connector A/E and A/F is in these limits ASM 216102:
| Temp (Deg.C) | OHMS |
|---|---|
| + 10 | 103.9 +/- 0.5 |
| + 20 | 107.8 +/- 0.5 |
| + 30 | 111.7 +/- 0.5 |
| + 50 | 119.4 +/- 0.5 |
| + 70 | 127.1 +/- 0.5 |
| + 100 | 138.5 +/- 0.5 |
- replace the SENSOR-COMPRESSOR TEMPERATURE [32HH] AMM 21-61-11-000-001 and AMM 21-61-11-400-001.
- do a check that the pack 2 ram-air inlet-flap is in the open position.
- do a check for a ground signal at the ACSC2 (57HH) connector AB/2C ASM 216101.
- do a check of the RELAY-WHEEL 3 SPEED [24GG] and replace it if necessary ASM 216101.
- do the test for the BSCU [10GG] as given in the AMM TASK 32-42-34-400-001 para. 5.A AMM 32-42-34-400-001.
(c) If the fault continues:
- replace the CONT-AIR COND SYSTEM 2 [57HH] AMM 21-61-34-000-002 and AMM 21-61-34-400-002.
- replace the SENSOR-DELTA P, PACK 2 [24HB2] AMM 21-51-11-000-001 and AMM 21-51-11-400-001.
E. For a Pack Outlet Overheat Condition
(1) If there is no airflow at the pack 2 ram-air outlet:
(a) If the resistance values are out of the specified limits:
(a) Remove the inspection panel from the pack 2 ram-air inlet plenum (11HM14).
(b) Do a check of the water injector nozzle for damage or wear:
Subtask 21-61-00-710-053-A (1) If there is no airflow at the pack 2 ram-air outlet:
- replace the MACHINE-AIR CYCLE [11HM1] AMM 21-52-21-000-001 and AMM 21-52-21-400-001.
- do a check that the resistance of the pack discharge sensor (34HH) measured between connector A/C and A/D and connector A/E and A/F is in these limits ASM 216102:
| Temp (Deg.C) | OHMS |
|---|---|
| + 10 | 18820 +/- 5 % |
| + 18 | 13340 +/- 5 % |
| + 25 | 10000 +/- 5 % |
| + 30 | 8197 +/- 5 % |
| + 40 | 5598 +/- 5 % |
| + 50 | 3903 +/- 5 % |
- replace the SENSOR-PACK OUTLET TEMP [34HH] AMM 21-61-15-000-001 and AMM 21-61-15-400-001.
(a) Remove the inspection panel from the pack 2 ram-air inlet plenum (11HM14).
(b) Do a check of the water injector nozzle for damage or wear:
- if the water injector nozzle is worn or damaged replace it AMM 21-52-00-960-001.
- if the main heat exchanger is clogged do the cleaning of the HEAT EXCHANGER-MAIN [11HM7] and the HEAT EXCHANGER-PRIMARY [11HM6] AMM 21-52-00-100-001.
- Install the inspection panel on the pack 2 ram-air inlet plenum (11HM14).
- do the cleaning of the clogged CONDENSER [11HM2] AMM 21-52-00-100-003,
- do the leak test of the condensor leakage AMM 21-52-00-790-001,
- do a check of the reheater (11HM3) for contamination AMM 21-52-00-780-001.
NOTE: This sub-paragraph (4) is only applicable to reheaters with the P/N 755A0000-04 and previous.
It is not applicable to reheaters with the P/N's 755A0000-04 Amendment A or subsequent.
(a) If the reheater is clogged: It is not applicable to reheaters with the P/N's 755A0000-04 Amendment A or subsequent.
- do the cleaning of the REHEATER [11HM3] AMM 21-52-00-100-002,
- replace the SENSOR-DELTA P, PACK 2 [24HB2] AMM 21-51-11-000-001 and AMM 21-51-11-400-001.
- replace the CONT-AIR COND SYSTEM 2 [57HH] AMM 21-61-34-000-002 and AMM 21-61-34-400-002.
F. Do the test as given in the Para. 3.A.
5. Close-upSubtask 21-61-00-860-051-A
A. Put the aircraft back to its initial configuration.