W DOC AIRBUS | TSM A320F

Failure of the Auxiliary Status Circuit of the BTC 2

TASK 24-20-00-810-873-A
Failure of the Auxiliary Status Circuit of the BTC 2

1. Possible Causes
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
ASM 242203
AMM 24-22-34-000-001
Removal of the GCU-1(2)
AMM 24-22-34-400-001
Installation of the GCU-1(2)
AMM 24-22-55-000-001
Removal of the Contactors
AMM 24-22-55-400-002
Installation of the Contactors
AMM 24-41-00-740-002
Operational Check of the GAPCU via the CFDS
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 31-60-00-860-002
EIS Stop Procedure
AMM 71-00-00-710-003
Engine Automatic Start
AMM 71-00-00-710-028
Engine Shutdown
AMM 71-00-00-860-814
Shutdown of the Engine
AMM 71-00-00-860-823
Start the Engine (Normal Automatic Start)
3. Fault Confirmation
Subtask 24-20-00-869-102-A ** ON A/C NOT FOR ALL
A. Test
Not applicable.
NOTE: As the GEN 2 was set to OFF because of a true failure, the fault confirmation is not necessary.
4. Fault Isolation
Subtask 24-20-00-810-196-A ** ON A/C NOT FOR ALL
A. If the fault symptom is identified by the CFDS message GCU2 (1XU2)/ BTC2 (11XU2) and the upper ECAM-DU warning GEN 2 FAULT:
   (1) If the fault continues:
  • do a check of the wiring ASM 242203 for a short to 28VDC between:
    . pin B/10J of the GCU 2 and pin C/3 of the ELEC/GEN 2 pushbutton switch (3XU2)
    . pin C/1 of the ELEC/GEN 2 pushbutton switch and pin A/A of the function relay (20XU)
    . pin A/1 of the function relay (20XU) and pin X/1 of the GLC 2 auxiliary control relay (4XU2).
     (a) If there is a short to 28VDC:
  • repair or replace as necessary.
     (b) If there is no short to 28VDC:
  • continue the trouble shooting procedure.
   (2) If the fault continues:
  • do a check of the wiring for a short to ground between pin B/29 of the BTC 2 and pin A/4C of the GCU 2 ASM 242203.
     (a) If there is a short to ground:
  • repair or replace as necessary.
     (b) If there is no short to ground:
  • do a check of the coil return wiring for a short to ground between pin B/5 of the BTC 2 and pin A/9A of the GCU 2 ASM 242203.
       1 If there is a short to ground:
  • repair or replace as necessary.
       2 If there is no short to ground:
  • do a check of the BTC 2 auxiliary status-contact between pin B/29 and pin B/27 (normally open) ASM 242203.
         a If there is no continuity:
Subtask 24-20-00-710-145-C ** ON A/C NOT FOR ALL
B. Do this operational test to make sure that the system operates correctly.
   (1) Aircraft Maintenance Configuration
     (a) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
     (b) Do the EIS start procedure (Upper ECAM DU and lower ECAM DU only)
AMM 31-60-00-860-001.
   (2) In the cockpit, on the ELEC panel 35VU:
  • Push, release and push again the GEN 2 pushbutton switch (3XU2).
   (3) Do the BITE test of the GAPCU AMM 24-41-00-740-002.
   (4) Start engine 2 AMM 71-00-00-860-823.
   (5) Do this test:
ACTION
RESULT
On the ECAM control panel:
  • Push the ELEC key to get the ELEC page.
On the lower ECAM DU:
  • The correct electrical parameters of GEN 2 are shown and GEN 2 supplies the AC2 busbar.
Subtask 24-20-00-710-145-F ** ON A/C NOT FOR ALL
B. Do this operational test to make sure that the system operates correctly.
   (1) Aircraft Maintenance Configuration
     (a) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
     (b) Do the EIS start procedure (Upper ECAM DU and lower ECAM DU only)
AMM 31-60-00-860-001.
   (2) On the ELEC panel 35VU:
  • push, release and push again the GEN 2 pushbutton switch (3XU2).
   (3) Do the operational test of the GAPCU AMM 24-41-00-740-002.
   (4) Start the engine 2 AMM 71-00-00-710-003.
   (5) Do this test:
ACTION
RESULT
On the ECAM control panel:
  • get the ELEC page.
On the lower ECAM DU:
  • the correct electrical parameters of the GEN 2 are shown and the AC2 busbar is supplied by the GEN 2.
5. Close-up
Subtask 24-20-00-860-175-C ** ON A/C NOT FOR ALL
A. Put the aircraft back to its initial configuration.
   (1) Stop engine 2 AMM 71-00-00-860-814.
   (2) Do the EIS stop procedure
AMM 31-60-00-860-002.
   (3) On the ECAM control panel, set the UPPER DISPLAY and LOWER DISPLAY potentiometers to OFF.
   (4) De-energize the aircraft electrical circuits
AMM 24-41-00-862-002.
Subtask 24-20-00-860-175-F ** ON A/C NOT FOR ALL
A. Put the aircraft back to its initial configuration.
   (1) Stop the engine 2 AMM 71-00-00-710-028.
   (2) Do the EIS stop procedure
AMM 31-60-00-860-002.
   (3) On the ECAM control panel, set the UPPER DISPLAY and LOWER DISPLAY potentiometers to OFF.
   (4) De-energize the aircraft electrical circuits
AMM 24-41-00-862-002.
[Rev.8 from Aug 2018] 2026.04.04 04:26:17 UTC
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