W DOC AIRBUS | TSM A320F

Failure of the External Power POR-Wiring or Interlock Protection

TASK 24-41-00-810-821-A
Failure of the External Power POR-Wiring or Interlock Protection

1. Possible Causes
  • wiring
  • RCPT-EXT PWR [20XG]
  • feeders
  • GAPCU [24XG]
  • external power
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)
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 24-41-00-710-070-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 24-41-00-810-065-B ** ON A/C NOT FOR ALL
A. If it is not possible to connect the external power source to the aircraft electrical network and if the fault symptom is identified by the CFDS message WRG: EXT PWR FEEDER/WRG: POR + CHECK INTLK:
  • stop the external power source,
  • disconnect the plug from the external power receptacle (20XG),
  • do a check for 28VDC at the pin F of the plug of the external power source.
   (1) If there is 28VDC:
  • do the trouble shooting of the pin F for a short to 28VDC between the plug and the external power source and repair as necessary.
   (2) If there is no 28VDC:
  • do a check of the wiring of the external power interlock-control ASM 244101 for a short circuit or a short to 28VDC between:
    . pin B/12E of the GAPCU and pin F of the external power receptacle (20XG)
    . pins F and E of the external power receptacle.
     (a) If the wiring is not correct:
     (b) If the wiring is correct:
  • do a check of the Point-Of-Regulation (POR) sense wiring ASM 244101 for a correct phase connection between:
    . terminal J of the EPC (3XG) and pin B/15J of the GAPCU (phase A)
    . terminal H of the EPC and pin B/14J of the GAPCU (phase B)
    . terminal G of the EPC and pin B/13J of the GAPCU (phase C).
       1 If the wiring is not correct:
  • connect the wiring as necessary to get the correct phase sequence.
       2 If the wiring is correct:
  • do a check of the external power feeders ASM 244101 for a correct phase connection between:
    . terminal A of the external power receptacle (20XG) and terminal K of the EPC (3XG)
    . terminal B of the external power receptacle and terminal L of the EPC
    . terminal C of the external power receptacle and terminal M of the EPC.
         a If the feeders are not correct:
  • connect the feeders as necessary to get the correct phase sequence.
         b If the feeders are correct:
         c If the fault continues:
  • replace the external power source.
Subtask 24-41-00-860-051-A ** ON A/C NOT FOR ALL
B. Make sure that the aircraft electrical circuits operate correctly in external power configuration.
   (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 04:26:54 UTC
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