W DOC AIRBUS | TSM A320F

Failure of the External Power Interlock-Wiring

TASK 24-41-00-810-829-A
Failure of the External Power Interlock-Wiring

1. Possible Causes
  • external power
  • external power plug
  • wiring
  • GAPCU [24XG]
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
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)
3. Fault Confirmation
Subtask 24-41-00-860-068-A ** ON A/C NOT FOR ALL
A. Test
   (1) Energize the aircraft electrical circuits from the external power AMM 24-41-00-861-002.
4. Fault Isolation
Subtask 24-41-00-810-091-A ** ON A/C NOT FOR ALL
A. If the test confirms the fault:
  • stop the external power source,
  • disconnect the plug from the external power receptacle (20XG),
  • make sure that the ELEC/EXT PWR pushbutton switch (10XG) is in the ON position,
  • do a check of the external power plug for a short to 28VDC of the pin F.
   (1) If there is a short to 28VDC:
  • repair or replace the external power plug .
   (2) If there is no short to 28VDC:
  • do a check and repair the wiring of the external power interlock-control ASM 244101 for a short to 28VDC or a short circuit between:
    . pin F and pin E of the external power receptacle (20XG)
    . pin B/12E of the GAPCU and pin F of the external power receptacle (20XG).
     (a) If the fault continues:
Subtask 24-41-00-860-069-A ** ON A/C NOT FOR ALL
B. Test
   (1) Energize the aircraft electrical circuits 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.
[Rev.8 from Aug 2018] 2026.04.04 04:26:55 UTC
"WTRUIB" 2025