W DOC AIRBUS | TSM A320F

The ON legend of the ELEC/EXT Pushbutton Switch Stays off when the EXT PWR Energizes the Aircraft

TASK 24-40-00-810-807-A
The ON legend of the ELEC/EXT Pushbutton Switch Stays off when the EXT PWR Energizes the Aircraft

1. Possible Causes
  • EPC [3XG]
  • wiring
  • LAMP
  • P/BSW-ELEC/EXT PWR [10XG]
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 24-41-55-000-001
Removal of the External Power Contactor (EPC)
AMM 24-41-55-400-001
Installation of the External Power Contactor (EPC)
AMM 33-14-00-710-001
Operational Test of the Lights
3. Fault Confirmation
Subtask 24-40-00-710-052-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.
NOTE: Energization of the aircraft is correct but, during the procedure given at Para. 3.F, make sure that:
  • on the panel 35VU, on the EXT PWR pushbutton switch, the AVAIL legend goes off and the ON legend stays off.
4. Fault Isolation
Subtask 24-40-00-810-056-A ** ON A/C NOT FOR ALL
A. If the test confirms the fault:
   (1) If the ON legend of the ELEC/EXT PWR pushbutton switch comes on:
     (a) If the fault continues:
  • do a check and repair the wiring between the pin A/5 of the ELEC/EXT PWR pushbutton switch and the pin A/17 of the EPC (3XG) and between the pin A/15 of the EPC (3XG) and the first terminal block.
   (2) If the ON legend of the ELEC/EXT PWR pushbutton switch stays off:
  • replace the LAMP of the ON legend of this pushbutton switch.
     (a) If the fault continues:
  • do a check of the wiring from the ELEC/EXT PWR pushbutton switch to the first terminal block ASM 244101.
       1 If there is no continuity:
  • repair the wiring.
       2 If there is continuity:
  • replace the P/BSW-ELEC/EXT PWR [10XG] .
Subtask 24-40-00-710-053-A ** ON A/C NOT FOR ALL
B. Do this test to make sure that the system operates correctly.
   (1) Do the test given in Para. 3. and make sure that:
  • on the panel 35VU, on the ELEC/EXT PWR pushbutton switch : the AVAIL legend goes off and the ON legend comes on.
   (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 04:26:52 UTC
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