W DOC AIRBUS | TSM A320F

Loss of the Oxygen Pressure Indication on the DOOR/OXY Page

TASK 35-10-00-810-801-A
Loss of the Oxygen Pressure Indication on the DOOR/OXY Page

1. Possible Causes
  • XMTR/PRESS REG-OXY [4HT]
  • wiring from the pressure regulator/transmitter (4HT) pin A/A, B to the first terminal block
  • wiring from the pressure regulator/transmitter (4HT) pin A/D to the ground terminal
  • wiring from the pressure regulator/transmitter (4HT) to the circuit breaker (1HT)
  • C/B-OXYGEN/CREW/OXY/SPLY [1HT]
  • wiring from the circuit breaker (1HT) to the pressure regulator/transmitter (4HT)
  • wiring from the pressure regulator/transmitter (4HT) pins A/A, B to the first terminal block
  • C/B-OXYGEN/CREW/OXY/SPLY
  • wiring
  • PRESS.TRANSM.REGULATO [4HT2]
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AMM 24-41-00-861-002
Energize the Aircraft Electrical Circuits from the External Power
AMM 24-41-00-862-002
De-energize the Aircraft Electrical Circuits Supplied from the External Power
AMM 31-60-00-860-001
EIS Start Procedure
AMM 35-13-00-00-
ASM 351301
AMM 35-13-15-000-001
Removal of the Oxygen Pressure Regulator/Transmitter
AMM 35-13-15-000-802
Removal of the Oxygen Pressure Regulator/Transmitters
AMM 35-13-15-400-001
Installation of the Oxygen Pressure Regulator/Transmitter
AMM 35-13-15-400-802
Installation of the Oxygen Pressure Regulator/Transmitters
3. Fault Confirmation
Subtask 35-10-00-860-050-A ** ON A/C NOT FOR ALL
A. Aircraft Maintenance Configuration
   (1) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
   (2) Do the EIS start procedure (Upper ECAM DU and lower ECAM DU only)
AMM 31-60-00-860-001.
   (3) On the panel 21VU, push the OXYGEN/CREW SUPPLY pushbutton switch (the OFF legend goes off).
Subtask 35-10-00-860-050-B ** ON A/C NOT FOR ALL
A. Aircraft Maintenance Configuration
   (1) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
   (2) Do the EIS start procedure (Upper ECAM DU and lower ECAM DU only)
AMM 31-60-00-860-001.
   (3) In the cockpit, on the OXYGEN section of the overhead control and indicating panel 21VU:
  • Push the CREW SUPPLY pushbutton switch (the OFF legend goes off).
   (4) In the avionics compartment:
     (a) Make sure that the two manual shutoff valves of the oxygen cylinders 5750HM1 and 5750HM2 are in the fully open position.
     (b) Make sure that the two pressure gages of the oxygen cylinders 5750HM1 and 5750HM2 show that they are not empty.
Subtask 35-10-00-865-050-A
B. Make sure that this(these) circuit breaker(s) is(are) closed:
PANELDESIGNATIONFINLOCATION
** ON A/C ALL
49VUOXYGEN/CREW/OXY/SPLY1HTHA01
Subtask 35-10-00-710-050-A ** ON A/C NOT FOR ALL
C. Test
   (1) On the ECAM control panel:
  • Push the DOOR key to get the DOOR/OXY page.
   (2) Make sure that the oxygen pressure indication is replaced by amber crosses on the DOOR/OXY page.
   (3) If the circuit breaker (1HT) trips:
  • Refer to Para. 4.A.(2).
Subtask 35-10-00-710-050-B ** ON A/C NOT FOR ALL
C. Test
   (1) On the ECAM control panel:
  • Push the DOOR key to get the DOOR/OXY page.
   (2) Make sure that a minimum of one of the two oxygen pressure indications is replaced with amber crosses on the DOOR/OXY page, AMM 35-13-00-00-.
NOTE: The pressure indication given on the left side of the lower ECAM DU is for the Captain and the Third Occupant. The pressure indication given on the right side of the lower ECAM DU is for the First Officer and the Fourth Occupant.
4. Fault Isolation
Subtask 35-10-00-810-050-A ** ON A/C NOT FOR ALL
A. If the test confirms the fault:
  • do a check of the circuit breaker (1HT) status:
   (1) If the circuit breaker (1HT) is closed:
  • do a check for 28VDC at pin A/C of the pressure regulator/transmitter (4HT) ASM 351301.
     (a) If there is 28VDC:
       1 If the fault continues:
  • do a check and repair the wiring from the pressure regulator/transmitter (4HT) pin A/A, B to the first terminal block ASM 351301.
     (b) If there is no 28VDC:
  • do a check for a ground signal at pin A/D of the pressure regulator/transmitter (4HT) ASM 351301.
       1 If there is no ground signal:
  • repair the wiring from the pressure regulator/transmitter (4HT) pin A/D to the ground terminal ASM 351301.
       2 If there is a ground signal:
  • do a check of the wiring from the pressure regulator/transmitter (4HT) to the circuit breaker (1HT) pin A/C to pin 2 ASM 351301.
         a If there is no continuity:
  • repair the above wiring.
         b If there is continuity:
   (2) If the circuit breaker is open:
  • close it.
     (a) If it trips:
       1 If the fault continues:
  • do a check for a short to ground at the wiring from the circuit breaker (1HT) to the pressure regulator/transmitter (4HT) pin 2 to pin A/C ASM 351301.
         a If there is a short to ground.
  • repair the above wiring.
         b If there is no short to ground.
  • do a check for a short to ground at the wiring from the pressure regulator/transmitter (4HT) pins A/A, B to the first terminal block ASM 351301.
       2 If there is a short to ground:
  • repair the above wiring.
       3 If there is no short to ground:
     (b) If the circuit breaker is still closed and if the fault continues:
Subtask 35-10-00-810-050-B ** ON A/C NOT FOR ALL
A. If the test confirms the fault on the two pressure indications:
  • Do a check of the circuit breaker (1HT) status:
   (1) If the circuit breaker (1HT) is closed:
  • Do a check of the wiring from the circuit breaker (1HT) to the first terminal block, ASM 351301.
     (a) If there is no continuity:
  • Repair the wiring.
     (b) If there is continuity:
  • Replace the C/B-OXYGEN/CREW/OXY/SPLY [1HT] .
   (2) If the circuit breaker is open:
  • Close it.
     (a) If it trips:
       1 Do a check for a short to ground at the wiring from the circuit breaker (1HT) pin 2 to the pressure regulator/transmitter (4HT) and (4HT2) pins A/C, ASM 351301.
       2 If there is a short to ground:
  • Repair the wiring.
       3 If there is no short to ground:
         a Do a check for a short to ground at the wiring from the pressure regulator/transmitters (4HT) and (4HT2) pins A/A, B to the first terminal block, ASM 351301.
         b If the fault continues:
  • Replace the C/B-OXYGEN/CREW/OXY/SPLY [1HT] .
     (b) If the circuit breaker is closed and if the fault continues:
       1 Replace the XMTR/PRESS REG-OXY [4HT] AMM 35-13-15-000-802 and AMM 35-13-15-400-802.
       2 If the fault continues:
Subtask 35-10-00-810-086-A ** ON A/C NOT FOR ALL
B. If the test confirms the fault on only one pressure indication:
   (1) If the pressure indication on the left side only is replaced with amber crosses:
  • Do a check for 28VDC at pin A/C of the pressure regulator/transmitter (4HT), ASM 351301.
     (a) If there is 28VDC:
       1 If the fault continues:
  • Do a check and repair the wiring from the pressure regulator/transmitter (4HT) pin A/A, B to the first terminal block, ASM 351301.
     (b) If there is no 28VDC:
  • Do a check for a ground signal at pin A/D of the pressure regulator/transmitter (4HT), ASM 351301.
       1 If there is no ground signal:
  • Repair the wiring from the pressure regulator/transmitter (4HT) pin A/D to the ground terminal, ASM 351301.
       2 If there is a ground signal:
  • Do a check of the wiring from the pressure regulator/transmitter (4HT) pin A/C to the circuit breaker (1HT) pin 2, ASM 351301.
         a If there is no continuity:
  • Repair the wiring.
   (2) If the pressure indication on the right side only is replaced with amber crosses:
  • Do a check for 28VDC at pin A/C of the pressure regulator/transmitter (4HT2), ASM 351301.
     (a) If there is 28VDC:
       1 If the fault continues:
  • Do a check and repair the wiring from the pressure regulator/transmitter (4HT2) pin A/A, B to the first terminal block, ASM 351301.
     (b) If there is no 28VDC:
  • Do a check for a ground signal at pin A/D of the pressure regulator/transmitter (4HT2), ASM 351301.
       1 If there is no ground signal:
  • Repair the wiring from the pressure regulator/transmitter (4HT2) pin A/D to the ground terminal, ASM 351301.
       2 If there is a ground signal:
  • Do a check of the wiring from the pressure regulator/transmitter (4HT2) pin A/C to the circuit breaker (1HT) pin 2, ASM 351301.
         a If there is no continuity:
  • Repair the wiring.
Subtask 35-10-00-710-051-A ** ON A/C NOT FOR ALL
C. Test
   (1) Make sure that the oxygen pressure indication comes on the DOOR/OXY page.
Subtask 35-10-00-710-051-B ** ON A/C NOT FOR ALL
C. Test
   (1) Make sure that the two oxygen pressure indications come on on the DOOR/OXY page.
5. Close-up
Subtask 35-10-00-860-057-A
A. Put the aircraft back to its initial configuration.
   (1) On the ECAM control panel, set the LOWER DISPLAY and the UPPER DISPLAY potentiometers to OFF.
   (2) In the cockpit, on the OXYGEN section of the overhead control and indicating panel 21VU:
  • Release the CREW SUPPLY pushbutton switch (the OFF legend comes on).
   (3) De-energize the aircraft electrical circuits
AMM 24-41-00-862-002.
[Rev.8 from Aug 2018] 2026.04.04 04:33:34 UTC
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