DOC AIRBUS | TSM A320FFWD Drainmast-Heater Failure
TASK 30-71-00-810-801-A
FWD Drainmast-Heater Failure
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
3. Fault Confirmation
Subtask 30-71-00-710-050-A ** ON A/C NOT FOR ALL Subtask 30-71-00-710-050-B ** ON A/C NOT FOR ALL 4. Fault Isolation
Subtask 30-71-00-810-050-A ** ON A/C NOT FOR ALL
Subtask 30-71-00-860-050-A
[Rev.8 from Aug 2018]
2026.04.04 04:29:45 UTC
FWD Drainmast-Heater Failure
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| TSM TASK 23-73-00-810-827-A | DEU-B - Fault in DEU-B 300RHx with connected systems/devices |
| AMM 23-73-47-000-001 | Removal of the Decoder/Encoder Unit B (300RH) |
| AMM 23-73-47-400-001 | Installation of the Decoder/Encoder Unit B (300RH) |
| AMM 30-71-00-710-001 | Operational Test of the Drainmast Ice Protection |
| AMM 30-71-00-740-001 | BITE Test of the Drainmast Ice Protection (through CIDS SYSTEM/TEST) |
| ASM 307101 | |
| AMM 30-71-34-000-001 | Removal of the Waste-Water Ice-Protection Control-Unit |
| AMM 30-71-34-400-001 | Installation of the Waste-Water Ice-Protection Control-Unit |
| AMM 30-71-51-000-001 | Removal of the Drain Mast |
| AMM 30-71-51-400-001 | Installation of the Drain Mast |
Subtask 30-71-00-710-050-A ** ON A/C NOT FOR ALL Subtask 30-71-00-710-050-B ** ON A/C NOT FOR ALL 4. Fault Isolation
Subtask 30-71-00-810-050-A ** ON A/C NOT FOR ALL
A. If the PTP 110RH shows the fault message DRAINMASTS HEATER FWD
(1) If the green HTR LED of CONTROL UNIT 5DU does not come on:
(a) Replace CONTROL UNIT, WASTE WATER ICE PROTECTION- [5DU] AMM 30-71-34-000-001 and AMM 30-71-34-400-001.
(b) If the fault continues:
1 Do a check of the resistance value of the drainmast heater and the temperature sensor. Refer to the resistance values in the tables.
(c) If the fault continues:
1 Replace DRAINMAST "F" [4DU] or only the cover or the heater tube assembly AMM 30-71-51-000-001 and AMM 30-71-51-400-001.
(d) If the fault continues:
1 Do a check and repair the wiring between:
(a) Do a check and repair the wiring if necessary between:
1 Replace DEU-B [300RH1] AMM 23-73-47-000-001 and AMM 23-73-47-400-001.
(c) If the fault continues:
1 Do the trouble shooting procedure for the fault in DEU-B 300RH1 with connected Systems/Devices (Ref. TSM TASK 23-73-00-810-827).
Subtask 30-71-00-810-050-B ** ON A/C NOT FOR ALL (1) If the green HTR LED of CONTROL UNIT 5DU does not come on:
(a) Replace CONTROL UNIT, WASTE WATER ICE PROTECTION- [5DU] AMM 30-71-34-000-001 and AMM 30-71-34-400-001.
(b) If the fault continues:
1 Do a check of the resistance value of the drainmast heater and the temperature sensor. Refer to the resistance values in the tables.
- Resistance values of the temperature sensor:
| TEMPERATURE | RESISTANCE VALUE IN OHM |
|---|---|
| -10deg C (14deg F) | 1784+-9 |
| 0deg C (32deg F) | 1854+-8 |
| +10deg C (50deg F) | 1926+-6 |
| +20deg C (68deg F) | 2000+-5 |
| +30deg C (86deg F) | 2076+-5 |
| +40deg C (104deg F) | 2153+-6 |
- Resistance values of the heater:
| PART NUMBER | RESISTANCE VALUE IN OHM |
|---|---|
| 4-60000H800-00 | 57+-3 |
| 4-60000H840-00 | 57+-3 |
| 4-60000H880-00 | 118+-5 |
| 4-60000H882-00 | 118+-5 |
| 4-60000H883-00 | 118+-5 |
(c) If the fault continues:
1 Replace DRAINMAST "F" [4DU] or only the cover or the heater tube assembly AMM 30-71-51-000-001 and AMM 30-71-51-400-001.
(d) If the fault continues:
1 Do a check and repair the wiring between:
- CONTROL UNIT 5DU connector A/8 and DRAINMAST 4DU connector A/B
- DRAINMAST 4DU connector A/C and GND
- DRAINMAST 4DU connector A/A and GND ASM 307101.
(a) Do a check and repair the wiring if necessary between:
- CONTROL UNIT 5DU connector A/11 and DEU-B 300RH1 connector C/34
- CONTROL UNIT 5DU connector A/14 and CB 1DU
- CONTROL UNIT 5DU connector A/15 and GND ASM 307101.
1 Replace DEU-B [300RH1] AMM 23-73-47-000-001 and AMM 23-73-47-400-001.
(c) If the fault continues:
1 Do the trouble shooting procedure for the fault in DEU-B 300RH1 with connected Systems/Devices (Ref. TSM TASK 23-73-00-810-827).
A. If the BITE test gives the maintenance message DRAINMAST HEATER FWD
(1) If the green HTR LED of CONTROL UNIT 5DU does not come on:
(a) Replace CONTROL UNIT, WASTE WATER ICE PROTECTION- [5DU] AMM 30-71-34-000-001 and AMM 30-71-34-400-001.
(b) If the fault continues:
1 Do a check of the resistance value of the drainmast heater and the temperature sensor. Refer to the resistance values in the tables.
1 Replace DRAINMAST "F" [4DU] or only the cover or the heater tube assembly AMM 30-71-51-000-001 and AMM 30-71-51-400-001.
(d) If the fault continues:
1 Do a check and repair the wiring between:
(a) Do a check and repair the wiring if necessary between:
1 Replace DEU-B [300RH1] AMM 23-73-47-000-001 and AMM 23-73-47-400-001.
(c) If the fault continues:
1 Do the trouble shooting procedure for the fault in DEU-B 300RH1 with connected Systems/Devices (Ref. TSM TASK 23-73-00-810-827).
Subtask 30-71-00-710-051-A (1) If the green HTR LED of CONTROL UNIT 5DU does not come on:
(a) Replace CONTROL UNIT, WASTE WATER ICE PROTECTION- [5DU] AMM 30-71-34-000-001 and AMM 30-71-34-400-001.
(b) If the fault continues:
1 Do a check of the resistance value of the drainmast heater and the temperature sensor. Refer to the resistance values in the tables.
- Resistance values of the temperature sensor:
--------------------------------------------------------- ! TEMPERATURE ! RESISTANCE VALUE IN OHM ! --------------------------------------------------------- ! -10deg C (14deg F) ! 1784+-9 ! !--------------------------!----------------------------! ! 0deg C (32deg F) ! 1854+-8 ! !--------------------------!----------------------------! ! +10deg C (50deg F) ! 1926+-6 ! !--------------------------!----------------------------! ! +20deg C (68deg F) ! 2000+-5 ! !--------------------------!----------------------------! ! +30deg C (86deg F) ! 2076+-5 ! !--------------------------!----------------------------! ! +40deg C (104deg F) ! 2153+-6 ! --------------------------------------------------------- - Resistance values of the heater:
-------------------------------------------------- ! PART NUMBER ! RESISTANCE VALUE IN OHM ! -------------------------------------------------- ! 4-60000H800-00 ! 57+-3 ! !-------------------!----------------------------! ! 4-60000H840-00 ! 57+-3 ! !-------------------!----------------------------! ! 4-60000H880-00 ! 118+-5 ! !-------------------!----------------------------! ! 4-60000H882-00 ! 118+-5 ! !-------------------!----------------------------! ! 4-60000H883-00 ! 118+-5 ! --------------------------------------------------
1 Replace DRAINMAST "F" [4DU] or only the cover or the heater tube assembly AMM 30-71-51-000-001 and AMM 30-71-51-400-001.
(d) If the fault continues:
1 Do a check and repair the wiring between:
- CONTROL UNIT 5DU connector A/8 and DRAINMAST 4DU connector A/B
- DRAINMAST 4DU connector A/C and GND
- DRAINMAST 4DU connector A/A and GND ASM 307101.
(a) Do a check and repair the wiring if necessary between:
- CONTROL UNIT 5DU connector A/11 and DEU-B 300RH1 connector C/43
- CONTROL UNIT 5DU connector A/14 and CB 1DU
- CONTROL UNIT 5DU connector A/15 and GND ASM 307101.
1 Replace DEU-B [300RH1] AMM 23-73-47-000-001 and AMM 23-73-47-400-001.
(c) If the fault continues:
1 Do the trouble shooting procedure for the fault in DEU-B 300RH1 with connected Systems/Devices (Ref. TSM TASK 23-73-00-810-827).
B. Do the test as given in Para. 3.A.
5. Close-upSubtask 30-71-00-860-050-A
A. Put the aircraft back to its initial configuration.