W DOC AIRBUS | TSM A320F

Failure of the External Ground Power Source

TASK 24-40-00-810-804-A
Failure of the External Ground Power Source

1. Possible Causes
  • external power source
  • RCPT-EXT PWR [20XG]
  • feeder wiring
  • wiring
  • GPCU [1XG]
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AMM 24-41-00-040-001
Visual Inspection of the External Power Receptacle
AMM 24-41-00-740-004
Operational Check of the GPCU 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
ASM 244101
AMM 24-41-34-000-001
Removal of the Ground Power Control Unit (GPCU)
AMM 24-41-34-400-001
Installation of the Ground Power Control Unit (GPCU)
AMM 24-41-51-000-001
Removal of the External Power Receptacle
AMM 24-41-51-400-001
Installation of the External Power Receptacle
3. Fault Confirmation
Subtask 24-40-00-860-056-A ** ON A/C NOT FOR ALL
A. Job Set-Up
   (1) Aircraft Maintenance Configuration
     (a) Energize the aircraft electrical circuits
AMM 24-41-00-861-002
Subtask 24-40-00-740-053-A ** ON A/C NOT FOR ALL
B. Test
Do the operational check of the GPCU with the CFDS AMM 24-41-00-740-004.
4. Fault Isolation
Subtask 24-40-00-810-053-A ** ON A/C NOT FOR ALL
A. If the test gives the maintenance message CHECK GROUND POWER:
  • Replace the external power source .
   (1) If the fault continues:
     (a) If the external power receptacle (20XG) is damaged:
     (b) If the external power receptacle (20XG) is not damaged:
  • Do a check of the feeder wiring for open circuit or short to ground between respectively the pins A, B, C of the external power receptacle (20XG) and the pins A/K, A/L, A/M of the EPC (3XG) ASM 244101.
       1 If the wiring is not correct:
  • Repair it.
       2 If the wiring is correct:
  • Do a check of the wiring for open circuit or short to ground between respectively the pins B/5C, B/6D, B/7C of the GPCU and the pins A/J, A/H, A/G of the EPC (3XG) ASM 244101.
         a If the wiring is not correct:
  • Repair it.
         b If the wiring is correct:
Subtask 24-40-00-700-057-A ** ON A/C NOT FOR ALL
B. Make sure that the aircraft electrical circuits operate correctly in ground configuration.
   (1) Energize the aircraft electrical circuit from the external power AMM 24-41-00-861-002.
   (2) De-energize the aircraft electrical circuits from the external power AMM 24-41-00-862-002.
5. Close-up
Subtask 24-40-00-860-057-A ** ON A/C NOT FOR ALL
A. Put the aircraft back to its initial configuration.
   (1) On the ECAM control panel, set the UPPER DISPLAY and LOWER DISPLAY potentiometers to OFF.
   (2) De-energize the aircraft electrical circuits
AMM 24-41-00-862-002
[Rev.8 from Aug 2018] 2026.04.04 04:26:52 UTC
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