W DOC AIRBUS | TSM A320F

Unwanted APU Leak Detection

TASK 36-22-00-810-850-A
Unwanted APU Leak Detection

1. Possible Causes
  • BMC-1 [1HA1]
  • sensing element
  • cable
  • SENSING ELEMENT-OVERHEAT,WING [11HF]
  • wiring
  • OVHT SENS ELEMENT [12HF]
  • OVHT SENS ELEMENT [13HF]
  • OVHT SENS ELEMENT [14HF]
  • OVHT SENS ELEMENT [15HF]
  • OVHT SENS ELEMENT [16HF]
  • OVHT SENS ELEMENT [17HF]
  • OVHT SENS ELEMENT [18HF]
  • OVHT SENS ELEMENT [19HF]
  • CABLE ASSY [20HF]
2. Job Set-up Information
 A. Fixtures, Tools, Test and Support Equipment
REFERENCE
QTY
DESIGNATION
9240SI
1
CONTROLLER-LOOP
 B. Referenced Information
REFERENCE
DESIGNATION
AMM 36-11-34-000-001
Removal of the BMC
AMM 36-11-34-400-001
Installation of the BMC
ASM 362201
AMM 36-22-17-000-001
Removal of the APU Overheat Sensing-Elements
AMM 36-22-17-400-001
Installation of the APU Overheat Sensing-Elements
3. Fault Confirmation
Subtask 36-22-00-710-096-A ** ON A/C NOT FOR ALL
A. Test
   (1) Not Applicable
4. Fault Isolation
Subtask 36-22-00-810-114-A ** ON A/C NOT FOR ALL
A. If there is the ECAM warning AIR APU BLEED LEAK and the FAULT legend is ON on the APU BLEED pushbutton switch:
   (1) Release and push the APU BLEED pushbutton switch to clean the warnings.
     (a) If the warning goes out of view:
  • No maintenance procedure is necessary.
     (b) If the warning stays in view:
  • Do the impedance check of the APU overheat detection loop.
       1 Remove the BMC1 (1HA1) AMM 36-11-34-000-001.
       2 On shelf 95VU, connect a 9240SI CONTROLLER-LOOP between BMC1 (1HA1) pin AA/4C and the ground ASM 362201.
  • Do an impedance check on the 9240SI CONTROLLER-LOOP.
     (c) If the impedance is more than 10 KOhms:
     (d) If the impedance is less than 10 KOhms:
  • Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 (1HA1) connector.
  • Do a visual inspection of the sensing elements and the cables on the APU loop.
     (e) If a sensing element or a cable is damaged:
     (f) If no sensing element is damaged:
  • Disconnect the connector between sensing elements 15HF and 16HF.
  • Connect the 9240SI CONTROLLER-LOOP between BMC1 (1HA1) pin AA/4C and the ground.
  • Do an impedance check on the 9240SI CONTROLLER-LOOP.
     (g) If the impedance is less than 10 KOhms:
  • Disconnect the connector between sensing elements 13HF and 14HF.
  • Do an impedance check on the 9240SI CONTROLLER-LOOP.
       1 If the impedance is less than 10 KOhms:
  • Disconnect the connector between cable 11HF and sensing element 12HF.
  • Do an impedance check on the 9240SI CONTROLLER-LOOP.
         a If the impedance is less than 10 KOhms:
  • Replace the SENSING ELEMENT-OVERHEAT,WING [11HF] AMM 36-22-17-000-001 and AMM 36-22-17-400-001.
  • Do an impedance check on the 9240SI CONTROLLER-LOOP.
    * If the impedance is less than 10 KOhms:
    ** Do a check and repair the wiring between BMC1 (1HF1) pin AA/4C and cable 11HF.
    ** Connect all the cables or disconnected connectors.
    ** Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 (1HA1) connector.
    - Install the BMC1 (1HA1) AMM 36-11-34-400-001.
    - Go to Para. 4.B.
    * If the impedance is more than 10 KOhms:
    - Connect all the cables or disconnected connectors.
    - Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 (1HA1) connector.
    - Install the BMC1 (1HA1) AMM 36-11-34-400-001.
    - Go to Para. 4.B.
         b If the impedance is more than 10 KOhms:
  • Disconnect the connector between sensing elements 12HF and 13HF.
  • Connect the connector between cable 11HF and sensing element 12HF.
  • Do an impedance check on the 9240SI CONTROLLER-LOOP.
    * If the impedance is less than 500 KOhms:
    ** Replace the OVHT SENS ELEMENT [12HF] AMM 36-22-17-000-001 and AMM 36-22-17-400-001.
    ** Connect all the cables or disconnected connectors .
    ** Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 (1HA1) connector.
    ** Install the BMC1 (1HA1) AMM 36-11-34-400-001.
    ** Go to Para. 4.B.
    * If the impedance is more than 500 KOhms:
    ** Replace the OVHT SENS ELEMENT [13HF] AMM 36-22-17-000-001 and AMM 36-22-17-400-001.
    ** Connect all the cables or disconnected connectors.
    ** Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 (1HA1) connector.
    ** Install the BMC1 (1HA1) AMM 36-11-34-400-001.
    ** Go to Para. 4.B.
       2 If the impedance is more than 10 KOhms:
  • Connect the connector between sensing elements 13HF and 14HF.
  • Disconnect the connector between sensing elements 14HF and 15HF.
  • Do an impedance check on the 9240SI CONTROLLER-LOOP.
         a If the impedance is less than 10 KOhms:
         b If the impedance is more than 10 kOhms:
     (h) If the impedance is more than 10 KOhms:
  • Connect the connector between sensing elements 15HF and 16HF.
  • Disconnect the connector between sensing elements 17HF and 18HF.
  • Do an impedance check on the 9240SI CONTROLLER-LOOP.
       1 If the impedance is less than 10 KOhms:
  • Disconnect the connector between sensing elements 16HF and 17HF.
  • Do an impedance check on the 9240SI CONTROLLER-LOOP.
         a If the impedance is less than 10 KOhms:
         b If the impedance is more than 10 KOhms:
       2 If the impedance is more than 10 KOhms:
  • Connect the connector between sensing elements 17HF and 18HF.
  • Disconnect the connector between sensing element 19HF and cable 20HF.
  • Do an impedance check on the 9240SI CONTROLLER-LOOP.
         a If the impedance is less than 10 KOhms:
  • Disconnect the connector between sensing elements 18HF and 19HF.
  • Do an impedance check on the 9240SI CONTROLLER-LOOP.
    * If the impedance is less than 10 KOhms:
    ** Replace the OVHT SENS ELEMENT [18HF] AMM 36-22-17-000-001 and AMM 36-22-17-400-001
    ** Connect all the cables or disconnected connectors.
    ** Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 (1HA1) connector.
    ** Install the BMC1 (1HA1) AMM 36-11-34-400-001.
    ** Go to Para. 4.B.
    * If the impedance is more than 10 KOhms:
    ** Replace the OVHT SENS ELEMENT [19HF] AMM 36-22-17-000-001 and AMM 36-22-17-400-001.
    ** Connect all the cables or disconnected connectors.
    ** Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 (1HA1) connector.
    ** Install the BMC1 (1HA1) AMM 36-11-34-400-001.
    ** Go to Para. 4.B.
         b If the impedance is more than 10 KOhms
  • Replace the CABLE ASSY [20HF] AMM 36-22-17-000-001 and AMM 36-22-17-400-001.
  • Connect all the cables or disconnected connectors.
  • Do an impedance check on the 9240SI CONTROLLER-LOOP.

  • If the impedance is less than 10 KOhms:
    * Do a check and repair the wiring between BMC1 (1HA1) pin AA/4C and cable 20HF.
    * Connect all the cables or disconnected connector.
    * Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 (1HA1) connector.
    * Install the BMC1 (1HA1) AMM 36-11-34-400-001.
    * Go to Para. 4.B.
    - If the impedance is more than 10 KOhms:
    * Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 (1HA1) connector.
    * Install the BMC1 (1HA1) AMM 36-11-34-400-001.
    * Go to Para. 4.B.
Subtask 36-22-00-710-097-A ** ON A/C NOT FOR ALL
B. After the subsequent flight, make sure that the fault does not continue.
[Rev.8 from Aug 2018] 2026.04.04 04:34:08 UTC
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