W DOC AIRBUS | TSM A320F

Unwanted DC BUS 1 FAULT Warning

TASK 24-60-00-810-806-A
Unwanted DC BUS 1 FAULT Warning

1. Possible Causes
  • SDAC-1 [1WV1]
  • SDAC-2 [1WV2]
  • wiring
  • C/B-EIS/SDAC1 AND 2/BUS1/28VDC [14WV]
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 246101
ASM 315408
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
3. Fault Confirmation
Subtask 24-60-00-860-058-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 24-60-00-865-051-A
B. Make sure that this(these) circuit breaker(s) is(are) closed:
PANELDESIGNATIONFINLOCATION
** ON A/C ALL
121VUEIS/SDAC1 AND 2/BUS1/28VDC14WVP04
125VU101PP/SPLY1PN1CD01
Subtask 24-60-00-710-060-A
C. Do this test:
ACTION
RESULT
On the ECAM control panel:
  • Push the ELEC key to get the ELEC page.
On the lower ECAM DU, on the ELEC page:
  • The normal configuration comes into view with the DC 1 busbar indication shown in amber.
On the upper ECAM DU:
  • The ELEC DC BUS 1 FAULT warning comes into view.
4. Fault Isolation
Subtask 24-60-00-810-055-A ** ON A/C NOT FOR ALL
A. If the test confirms the fault:
  • Do a check of the status of the EIS/SDAC1 & 2/BUS1/28VDC circuit breaker (14WV).
   (1) If the circuit breaker is closed:
     (a) If the fault does not continue:
     (b) If the fault continues:
       1 If the fault does not continue:
       2 If the fault continues:
  • Do a check and repair the wiring between:
    . 28VDC BUS 1 (101PP) and the first branch point, the EIS/SDAC1 & 2/BUS1/28VDC circuit breaker (14WV) included
    . 28VDC BUS 1 (101PP) and pin E of the TR1 contactor (5PU1), the 101PP SPLY circuit breaker (1PN1) included, ASM 315408 and ASM 246101.
  • Install SDAC2 AMM 31-55-34-400-001.
   (2) If the circuit breaker is open:
     (a) If the fault continues:
  • Replace C/B-EIS/SDAC1 AND 2/BUS1/28VDC [14WV] .
Subtask 24-60-00-810-055-B ** ON A/C NOT FOR ALL
A. If the test confirms the fault:
  • Do a check of the status of the EIS/SDAC1 & 2/BUS1/28VDC circuit breaker (14WV).
   (1) If the circuit breaker is closed:
     (a) If the fault does not continue:
     (b) If the fault continues:
       1 If the fault does not continue:
       2 If the fault continues:
  • Do a check and repair the wiring between:
    . 28VDC BUS 1 (101PP) and the first branch point, the EIS/SDAC1 & 2/BUS1/28VDC circuit breaker (14WV) included
    . 28VDC BUS 1 (101PP) and pin 10 of the module 13PN, the 101PP SPLY circuit breaker (1PN1) included, ASM 315408 and ASM 246101.
  • Install SDAC2 AMM 31-55-34-400-001.
   (2) If the circuit breaker is open:
     (a) If the fault continues:
  • Replace C/B-EIS/SDAC1 AND 2/BUS1/28VDC [14WV] .
Subtask 24-60-00-710-061-A
B. Do this test to make sure that the system operates correctly:
ACTION
RESULT
On the ECAM control panel:
  • Push the ELEC key to get the ELEC page.
On the lower ECAM DU, on the ELEC page:
  • The normal configuration comes into view.
On the upper ECAM DU:
  • No message comes into view.
5. Close-up
Subtask 24-60-00-860-059-A
A. Put the aircraft back to its initial configuration.
   (1) On the ECAM control panel, set the UPPER DISPLAY and LOWER DISPLAY potentiometers to OFF.
   (2) De-energize the aircraft electrical circuits
AMM 24-41-00-862-002.
[Rev.8 from Aug 2018] 2026.04.04 04:26:58 UTC
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