W DOC AIRBUS | TSM A320F

Failure of the External Power and of the POR Sense Wiring of the GAPCU

TASK 24-41-00-810-814-A
Failure of the External Power and of the POR Sense Wiring of the GAPCU

1. Possible Causes
  • external power
  • GAPCU [24XG]
  • C/B-GND/PWR/PROT [2XG]
  • wiring
  • feeders
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
TSM TASK 24-00-00-810-803-A
Circuit Breaker Tripped and/or C/B TRIPPED Warning
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 24-41-00-860-061-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 24-41-00-810-078-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)
  • repair or replace the external power source
  • energize the aircraft electrical circuits from the external power AMM 24-41-00-861-002.
   (1) If the external power energizes the electrical circuits:
  • stop the trouble shooting.
   (2) If the external power does not energize the electrical circuits:
     (a) If the fault continues:
  • do the trouble shooting given in Para. 4.B.
Subtask 24-41-00-810-079-A ** ON A/C NOT FOR ALL
B. If the external power does not energize the electrical circuits:
  • Do a check of the status of the GND/PWR/PROT circuit breaker (2XG).
   (1) If the circuit breaker is open:
     (a) If the fault continues:
  • Replace the C/B-GND/PWR/PROT [2XG] .
   (2) If the GND/PWR/PROT circuit breaker (2XG) is closed:
  • Do a check of the Point-Of-Regulation (POR) sense wiring ASM 244101 for an open circuit or a short circuit between:
    . pin A/J of the EPC (3XG) and pin B/15J of the GAPCU
    . pin A/H of the EPC and pin B/14J of the GAPCU
    . pin A/G of the EPC and pin B/13J of the GAPCU.
     (a) If the wiring is not correct:
  • Repair or replace as necessary.
     (b) If the wiring is correct:
  • Do a check of the external power feeders ASM 244101 for an open circuit, a short circuit or a short to airframe between:
    . pin A of the external power receptacle (20XG) and pin A/K of the EPC (3XG)
    . pin B of the external power receptacle and pin A/L of the EPC
    . pin C of the external power receptacle and pin A/M of the EPC.
       1 If the feeders are not correct:
  • Repair or replace as necessary.
       2 If the feeders are correct:
Subtask 24-41-00-860-062-A ** ON A/C NOT FOR ALL
C. Do this procedure to make sure that the system operates correctly.
   (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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