W DOC AIRBUS | TSM A320F

Failure of the AC ESS Switching Circuit with AC1 busbar Available

TASK 24-50-00-810-818-A
Failure of the AC ESS Switching Circuit with AC1 busbar Available

1. Possible Causes
  • P/BSW-ELEC/AC ESS FEED [11XC]
  • RELAY-ESS NTWK AUTO SWTG (17XC)
  • RELAY-BUS 1XP CTL (20XN1)
  • wiring
  • SDAC-1 [1WV1]
  • SDAC-2 [1WV2]
  • RELAY-CNTOR 3XC MONG, 2
  • CNTOR-AC ESS BUS SWITCHING [3XC]
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
ASM 242502
AMM 24-25-55-000-001
Removal of the AC Essential Bus Switching Contactor
AMM 24-25-55-400-001
Installation of the AC Essential Bus Switching Contactor
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
AMM 31-55-34-000-001
Removal of the SDAC
AMM 31-55-34-400-001
Installation of the SDAC
AMM 31-60-00-860-001
EIS Start Procedure
AMM 31-60-00-860-002
EIS Stop Procedure
3. Fault Confirmation
Subtask 24-50-00-860-080-A
A. Job Set-up
   (1) Aircraft Maintenance Configuration
     (a) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
     (b) Do the EIS start procedure (Upper ECAM DU and lower ECAM DU only)
AMM 31-60-00-860-001.
Subtask 24-50-00-710-084-A
B. Test
   (1) On the ECAM control panel:
  • Push the ELEC key to get the ELEC page.
   (2) On the lower ECAM display unit if:
     (a) There is only a green line between the AC ESS busbar and the AC2 busbar, go to the Para. Fault Isolation A.
     (b) There is a green line between the AC ESS busbar and the AC1 busbar and, there is a green line between the AC ESS busbar and the AC2 busbar, go to the Para. Fault Isolation B.
4. Fault Isolation
Subtask 24-50-00-810-069-A
A. If the test confirms the fault:
  • Open the circuit breaker ESS NTWK AUTO ALTN (6XC).
   (1) If the AC ESS BUS ALTN warning is still present:
  • Replace the P/BSW-ELEC/AC ESS FEED [11XC] .
     (a) If the fault continues:
  • Replace the RELAY-ESS NTWK AUTO SWTG (17XC).
   (2) If the AC ESS BUS ALTN warning goes out of view:
  • Replace the RELAY-ESS NTWK AUTO SWTG (17XC).
     (a) If the fault continues:
  • Replace the RELAY-BUS 1XP CTL (20XN1).
     (b) If the fault continues:
  • Do a check and repair the wiring ASM 242502 between:
    . Pin A/X2 of the RELAY-ESS NTWK AUTO SWTG (17XC) and pin A/A2 of the RELAY-BUS 2XP CTL (20XN2)
    . Pin A/A1 of the RELAY-BUS 2XP CTL (20XN2) and pin A/A2 of the RELAY-BUS 1XP CTL (20XN1)
    . Pin A/A3 of the RELAY-BUS 1XP CTL (20XN1) and the ground.
Subtask 24-50-00-810-070-A
B. If the test confirms the fault:
   (1) If the fault continues:
   (2) If the fault continues:
  • Replace the RELAY-CNTOR 3XC MONG, 2.
   (3) If the fault continues:
     (a) Remove the SDAC-1 [1WV1] AMM 31-55-34-000-001.
     (b) Do a check for absence of GND at the SDAC1 connector AD pin 5H:
       1 If there is a short to ground:
  • Repair the related wiring.
     (c) Install the SDAC-1 [1WV1] AMM 31-55-34-400-001.
     (d) Remove the SDAC-2 [1WV2] AMM 31-55-34-000-001.
     (e) Do a check for absence of GND at the SDAC2 connector AD pin 5H:
       1 If there is a short to ground:
  • Repair the related wiring.
     (f) Install the SDAC-2 [1WV2] AMM 31-55-34-400-001.
   (4) If the fault continues:
5. Close-up
Subtask 24-50-00-710-085-A
A. Do the test given in Para. 3.
Subtask 24-50-00-860-081-A
B. Put the aircraft back to its initial configuration.
   (1) Do the EIS stop procedure
AMM 31-60-00-860-002.
   (2) De-energize the aircraft electrical circuits
AMM 24-41-00-862-002.
[Rev.8 from Aug 2018] 2026.04.04 04:26:57 UTC
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