Pack 1 High Discharge Temperature
TASK 21-61-00-810-832-A
Pack 1 High Discharge Temperature
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 21-61-00-710-112-C ** ON A/C NOT FOR ALL
Subtask 21-61-00-810-270-A ** ON A/C NOT FOR ALL
Subtask 21-61-00-860-081-A
[Rev.8 from Aug 2018]
2026.04.04 04:24:55 UTC
Pack 1 High Discharge Temperature
1. Possible Causes
- P1 PACK DISCH PRESS SENSOR [14HH]
- ram-air inlet door mechanism
- MACHINE-AIR CYCLE [10HM1]
- SENSOR-WATER EXTRACTOR TEMPERATURE [11HH]
- water injector nozzle
- clogged main heat exchanger
- clogged primary heat exchanger
- P1 CONTROLLER [7HH]
- SENSOR-PACK OUTLET PNEUMATIC [10HM10]
- VALVE-ANTI ICE [17HH]
- wiring
- VALVE-TURBINE BYPASS [10HH]
- REHEATER [10HM3]
- CONDENSER [10HM2]
- P1 FLOW CTL VALVE [11HB]
- water drain line
- HEAT EXCHANGER-MAIN [10HM7]
- HEAT EXCHANGER-PRIMARY [10HM6]
- CONT-AIR COND SYSTEM 1 [47HH]
- FLOW CTL UNIT - PACK 1 [23HB]
- P1 PRESS INL SENSOR [16HH]
- SENSOR-PRESS, PACK 1 INLET [23HB1]
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| AMM 12-33-21-618-001 | Pre-conditioning through the LP Ground Connection |
| 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 21-52-00-780-001 | Pressure Drop Test of the Reheater |
| AMM 21-52-00-960-001 | Replacement of the Water Injector Nozzle |
| AMM 21-52-16-000-001 | Removal of the Water Extractor |
| AMM 21-52-16-400-001 | Installation of the Water Extractor |
| 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 21-52-42-000-001 | Removal of the Water Injector |
| AMM 21-52-42-400-001 | Installation of the Water Injector |
| ASM 216103 | |
| ASM 216104 | |
| AMM 21-61-13-000-001 | Removal of the Water-Extractor Temperature Sensors |
| AMM 21-61-13-400-001 | Installation of the Water-Extractor Temperature Sensors |
| AMM 21-61-14-000-001 | Removal of the Pack Discharge Pressure Sensor |
| AMM 21-61-14-400-001 | Installation of the Pack Discharge Pressure Sensor |
| AMM 21-61-16-000-001 | Removal of the Pack-Inlet Pressure Sensor |
| AMM 21-61-16-400-002 | Installation of the Pack-Inlet Pressure Sensor |
| AMM 21-61-19-000-001 | Removal of the Pack-Outlet Pneumatic Sensor |
| AMM 21-61-19-400-002 | Installation of the Pack-Outlet Pneumatic Sensor |
| 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 21-61-51-000-003 | Removal of the Air-Inlet Flap Mechanism |
| AMM 21-61-51-400-003 | Installation of the Air-Inlet Flap Mechanism |
| AMM 21-61-53-000-001 | Removal of the Turbine Bypass Valve |
| AMM 21-61-53-400-001 | Installation of the Turbine Bypass Valve |
| AMM 21-63-00-720-001 | Functional Test of the Cockpit and Cabin Temperature Control without CFDS/MCDU. |
| AMM 32-69-00-740-001 | BITE Check of Landing-Gear Control Interface-Unit (LGCIU) With Use of MCDU to Ensure that Continuous BITE is Operative |
Subtask 21-61-00-710-112-C ** ON A/C NOT FOR ALL
A. Test
(2) Do the pre-conditioning with the APU AMM 12-33-21-618-001.
(3) Make sure that the pack 1 inlet-pressure indication on the ECAM BLEED page is > 20 PSI.
(4) Set the selectors COCKPIT, FWD CABIN and AFT CABIN, which are installed on the panel 30VU, to HOT for 10 minutes.
(5) Check of ram-air outlet airflow
(6) Set the selectors COCKPIT, FWD CABIN and AFT CABIN to COLD.
(7) On the ECAM BLEED page do a check of the pack 1 discharge temperature (referred to as PDT 1).
Subtask 21-61-00-710-112-D ** ON A/C NOT FOR ALL NOTE: Do the steps (6) and (7) in less than 120 s, if not, the control of the zone temperature stabilizes.
(1) Do the check of the ram-air inlet door mechanism for excessive backlash. (2) Do the pre-conditioning with the APU AMM 12-33-21-618-001.
(3) Make sure that the pack 1 inlet-pressure indication on the ECAM BLEED page is > 20 PSI.
(4) Set the selectors COCKPIT, FWD CABIN and AFT CABIN, which are installed on the panel 30VU, to HOT for 10 minutes.
(5) Check of ram-air outlet airflow
WARNING:
BE CAREFUL WHEN YOU DO THIS PROCEDURE. THE AIRFLOW CAN BE HOT AND HOT AIR CAN CAUSE BURNS.
(a) Do a check to see that there is airflow at the pack 1 ram-air outlet. (6) Set the selectors COCKPIT, FWD CABIN and AFT CABIN to COLD.
(7) On the ECAM BLEED page do a check of the pack 1 discharge temperature (referred to as PDT 1).
NOTE: The PDT 1 increases regularly (because of the pack de-icing operation).
A. Test
(2) Do the pre-conditioning with the APU AMM 12-33-21-618-001.
(3) Make sure that the pack 1 inlet-pressure indication on the ECAM BLEED page is > 20 PSI.
(4) Set the selectors COCKPIT, FWD CABIN and AFT CABIN, which are installed on the panel 30VU, to HOT for 10 minutes.
(5) Check of ram-air outlet airflow
(6) Set the selectors COCKPIT, FWD CABIN and AFT CABIN to COLD.
(7) On the ECAM BLEED page do a check of the pack 1 discharge temperature (referred to as PDT 1).
4. Fault IsolationNOTE: Do the steps (6) and (7) in less than 120 s, if not, the control of the zone temperature stabilizes.
(1) Do the check of the ram-air inlet door mechanism for excessive backlash. (2) Do the pre-conditioning with the APU AMM 12-33-21-618-001.
(3) Make sure that the pack 1 inlet-pressure indication on the ECAM BLEED page is > 20 PSI.
(4) Set the selectors COCKPIT, FWD CABIN and AFT CABIN, which are installed on the panel 30VU, to HOT for 10 minutes.
(5) Check of ram-air outlet airflow
WARNING:
BE CAREFUL WHEN YOU DO THIS PROCEDURE. THE AIRFLOW CAN BE HOT AND HOT AIR CAN CAUSE BURNS.
(a) Do a check to see that there is airflow at the pack 1 ram-air outlet. (6) Set the selectors COCKPIT, FWD CABIN and AFT CABIN to COLD.
(7) On the ECAM BLEED page do a check of the pack 1 discharge temperature (referred to as PDT 1).
Subtask 21-61-00-810-270-A ** ON A/C NOT FOR ALL
A. If the bypass valve (10HH) is always in half open position:
Subtask 21-61-00-810-141-B - replace the P1 PACK DISCH PRESS SENSOR [14HH] AMM 21-61-14-000-001 and AMM 21-61-14-400-001.
B. If the ram-air inlet doors are closed and the ram-air inlet door-mechanism has more than 20mm backlash:
Subtask 21-61-00-810-129-A - replace the ram-air inlet door mechanism AMM 21-61-51-000-003 and AMM 21-61-51-400-003.
- replace the MACHINE-AIR CYCLE [10HM1] AMM 21-52-21-000-001 and AMM 21-52-21-400-001.
C. If the PDT 1 is below 10 Deg.C (during the test para. 3.A.(4), (6), (7)):
Subtask 21-61-00-810-130-A ** ON A/C NOT FOR ALL - no other maintenance action is necessary.
D. If the PDT 1 is above 10 Deg.C for less than 11 minutes, with the selectors COCKPIT, FWD CABIN and AFT CABIN, which are installed on the panel 30VU, set to COLD:
Subtask 21-61-00-810-131-A ** ON A/C NOT FOR ALL - no other maintenance action is necessary.
E. If the PDT 1 is above 10 Deg.C for more than 11 minutes, with the selectors COCKPIT, FWD CABIN and AFT CABIN, which are installed on the panel 30VU, set to COLD:
(a) If the resistance values are out of the specified limits:
(a) Remove the inspection panel from the pack 1 ram-air inlet plenum (10HM14),
(b) Do a check of the water injector nozzle for damage or wear:
(4) If the fault continues:
Subtask 21-61-00-810-142-A ** ON A/C NOT FOR ALL - open and close the CBs 1HH, 2HH, 3HH, and 4HH.
- do the functional test of the cockpit and cabin temperature control system AMM 21-63-00-720-001.
- do a check that the resistance of the water extractor temperature sensor (11HH) measured between connector A/E and A/F and connector A/C and A/D is in these limits ASM 216104:
| 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-WATER EXTRACTOR TEMPERATURE [11HH] AMM 21-61-13-000-001 and AMM 21-61-13-400-001.
(a) Remove the inspection panel from the pack 1 ram-air inlet plenum (10HM14),
(b) Do a check of the water injector nozzle for damage or wear:
- replace the water injector nozzle if it is worn or damaged AMM 21-52-00-960-001.
- if the main heat exchanger is clogged do the cleaning of the clogged main heat exchanger and the clogged primary heat exchanger AMM 21-52-00-100-001.
(4) If the fault continues:
- replace the P1 CONTROLLER [7HH] AMM 21-61-34-000-001 and AMM 21-61-34-400-001.
- do a check of the position of the manual override lever of the pack 1 anti-ice valve (17HH).
- disconnect the electrical connector (17HHA) AMM 21-61-41-000-001.
- do a check for 28 VDC at the electrical connector (17HHA) between pins A and B ASM 216104.
- replace the SENSOR-PACK OUTLET PNEUMATIC [10HM10] AMM 21-61-19-000-001 and AMM 21-61-19-400-002.
- replace the VALVE-ANTI ICE [17HH] AMM 21-61-41-000-001 and AMM 21-61-41-400-001.
- do a check and repair the wiring if necessary between:
VALVE (17HH) connector A/A and PC 1 (7HH) connector AB/8A,
VALVE (17HH) connector A/B and GND,
VALVE (17HH) connector A/C and GND ASM 216104.
- replace the VALVE-TURBINE BYPASS [10HH] AMM 21-61-53-000-001 and AMM 21-61-53-400-001.
- do a check of the reheater (10HM3) for contamination AMM 21-52-00-780-001.
NOTE: This sub-paragraph 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 [10HM3] AMM 21-52-00-100-002,
- do the cleaning of the CONDENSER [10HM2] AMM 21-52-00-100-003,
- do a check of the position of the manual override lever of the pack 1 flow control-valve (11HB).
- replace the P1 FLOW CTL VALVE [11HB] AMM 21-51-51-000-001 and AMM 21-51-51-400-001.
- do a check of the water drain line between the extractor (10HM8) and the injector (20HM) and the injector nozzle (20HM) for contamination and clean it if necessary AMM 21-52-16-000-001, AMM 21-52-16-400-001, AMM 21-52-42-000-001 and AMM 21-52-42-400-001.
F. If you cannot confirm this fault on the ground, but during the last flight a high PDT 1 (above 10 Deg.C) was reported:
(b) If there is a ground signal:
Subtask 21-61-00-810-131-D ** ON A/C NOT FOR ALL - replace the P1 PRESS INL SENSOR [16HH] AMM 21-61-16-000-001 and AMM 21-61-16-400-002.
- do a check for a ground signal at the PC 1 (7HH) connector AA/9B ASM 216103.
- do a check and repair the wiring if necessary between:
PC 1 (7HH) connector AA/9B and LGCIU 2 (5GA2) connector AB/G1 ASM 216103.
- do the BITE test of the landing gear AMM 32-69-00-740-001.
(b) If there is a ground signal:
- replace the P1 CONTROLLER [7HH] AMM 21-61-34-000-001 and AMM 21-61-34-400-001.
G. If the PDT 1 is above 10 Deg.C with the selectors COCKPIT, FWD CABIN and AFT CABIN, which are installed on the panel 30VU, set to COLD:
(a) Remove the inspection panel on the pack 1 ram-air inlet plenum (10HM14).
(b) Do a check of the water injector nozzle for damage or wear:
(3) If the fault continues:
Subtask 21-61-00-810-142-B ** ON A/C NOT FOR ALL - open and close the CBs 49HH, 50HH, 51HH and 52HH.
- do the functional test of the cockpit and cabin temperature control system AMM 21-63-00-720-001.
(a) Remove the inspection panel on the pack 1 ram-air inlet plenum (10HM14).
(b) Do a check of the water injector nozzle for damage or wear:
- replace the water injector nozzle if it is worn or damaged AMM 21-52-00-960-001.
- if the main heat exchanger is clogged do the cleaning of the HEAT EXCHANGER-MAIN [10HM7] and the HEAT EXCHANGER-PRIMARY [10HM6] AMM 21-52-00-100-001.
(3) If the fault continues:
- do a check that the resistance of the water extractor temperature sensor (11HH) measured between connector A/E and A/F and connector A/C and A/D is in these limits ASM 216104:
-------------------------------- !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-WATER EXTRACTOR TEMPERATURE [11HH] AMM 21-61-13-000-001 and AMM 21-61-13-400-001.
- replace the CONT-AIR COND SYSTEM 1 [47HH] AMM 21-61-34-000-002 and AMM 21-61-34-400-002.
- replace the VALVE-TURBINE BYPASS [10HH] AMM 21-61-53-000-001 and AMM 21-61-53-400-001.
- do a check of the reheater (10HM3) for contamination AMM 21-52-00-780-001.
NOTE: This sub-paragraph 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 [10HM3] AMM 21-52-00-100-002,
- do the cleaning of the CONDENSER [10HM2] AMM 21-52-00-100-003,
- do a check of the position of the manual override lever of the pack 1 flow control-system (23HB).
- replace the FLOW CTL UNIT - PACK 1 [23HB] AMM 21-51-51-000-001 and AMM 21-51-51-400-001.
- do a check of the water drain line between the extractor (10HM8) and the injector (20HM) and the injector nozzle (20HM) for contamination and clean it if necessary AMM 21-52-16-000-001, AMM 21-52-16-400-001, AMM 21-52-42-000-001 and AMM 21-52-42-400-001.
H. If you cannot confirm this fault on the ground, but during the last flight a high PDT 1 (above 10 Deg.C) was reported:
(b) If there is a ground signal:
Subtask 21-61-00-710-113-A - replace the SENSOR-PRESS, PACK 1 INLET [23HB1] AMM 21-61-16-000-001 and AMM 21-61-16-400-002.
- do a check for a ground signal at the ACSC1 (47HH) connector AB/2H ASM 216103.
- do a check and repair the wiring if necessary between:
ACSC1 (47HH) connector AB/2H and LGCIU 2 (5GA2) connector AB/1G ASM 216103.
- do the BITE test of the landing gear AMM 32-69-00-740-001.
(b) If there is a ground signal:
- replace the CONT-AIR COND SYSTEM 1 [47HH] AMM 21-61-34-000-002 and AMM 21-61-34-400-002.
I. Do the test as given in the Para. 3.A.
5. Close-upSubtask 21-61-00-860-081-A
A. Put the aircraft back to its initial configuration.