W DOC AIRBUS | TSM A320F

Failure of the Contactor in Closed Position

TASK 24-35-00-810-801-A
Failure of the Contactor in Closed Position

1. Possible Causes
  • CNTOR-DC ESS BUS SUPPLY [4PC]
  • CNTOR-DC NORM BUS 1 SWITCHING [1PC1]
  • wiring
  • diode module (2420VD)
  • C/B-ELEC/CNTOR/ESS/DC BUS/TIE [3PC]
  • TIMER [33XE]
  • CNTOR-DC NORM BUS 2 SWITCHING [1PC2]
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
ASM 243501
ASM 243502
AWM 243503
AMM 24-35-55-000-001
Removal of the Contactor
AMM 24-35-55-000-002
Removal of the Contactor
AMM 24-35-55-400-001
Installation of the Contactor
AMM 24-35-55-400-002
Installation of the 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 31-60-00-860-001
EIS Start Procedure
AMM 31-60-00-860-002
EIS Stop Procedure
3. Fault Confirmation
Subtask 24-35-00-860-050-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 24-35-00-710-050-A
B. Test
   (1) Do this test:
ACTION
RESULT
On the ECAM control panel:
  • Push the ELEC key to get the ELEC page.
On the lower ECAM display unit:
  • The TR1 and the TR2 supply the DC1 and DC2 busbars.
  • The line between DC BAT BUS and DC ESS BUS comes into view.
  • The green line between DC2 and DC BAT BUS is not shown.
   (2) If the test confirms the fault:
  • Do the fault isolation procedure given in step B.
   (3) If the green line between DC2 and DC BAT BUS is shown:
  • Do the fault isolation procedure given in step C.
   (4) If the green line between DC2 and DC BAT BUS is not shown:
  • Do the fault isolation procedure given in step D.
Subtask 24-35-00-710-058-A
C. If the test is correct, do this test:
ACTION
RESULT
On the panel 125VU(124VU):
  • Open the circuit breaker 4PU1(2).
On the upper ECAM display unit:
  • The TR1(2) FAULT indication comes into view.
    On the lower ECAM display unit:
  • The TR1(2) no longer supplies the DC1(2) busbar.
  • The DC2(1) busbar supplies the DC1(2) busbar through the DC BAT busbar.
  • The AC ESS busbar supplies the DC ESS busbar through the ESS TR.
4. Fault Isolation
Subtask 24-35-00-810-050-A
A. If the test confirms the fault:
  • Do a check for 28 VDC between pins B/3 and B/5 of the DC ESS BUS SPLY contactor (4PC).
   (1) If there is 28 VDC:
   (2) If there is no 28 VDC:
  • Do a check of the status of the circuit breaker (3PC).
     (a) If the circuit breaker is closed:
  • Do a check for 28 VDC between pins B/3 and B/5 of the DC NORM BUS 1 switching-contactor (1PC1).
       1 If there is 28 VDC:
         a If the fault continues:
  • Do a check and repair the wiring :
    . Between the circuit breaker (3PC) and pin B/3 of the contactor (4PC)
    . Between pin B/5 of the contactor (4PC) and the ground point or terminal block ASM 243501 AWM 243503.
       2 If there is no 28 VDC:
  • Do a check of the wiring :
    . Between the circuit breaker (9PC) and pin B/3 of the DC NORM BUS 1 switching-contactor (1PC1)
    . Between pin B/5 of the DC NORM BUS 1 switching-contactor (1PC1) and the ground ASM 243502.
         a If the wiring is not correct:
  • Repair the wiring .
         b If the wiring is correct:
  • Replace the diode module (2420VD).
     (b) If the circuit breaker is open:
       1 If the fault continues:
  • Replace the C/B-ELEC/CNTOR/ESS/DC BUS/TIE [3PC] .
Subtask 24-35-00-810-052-A
B. If the TR1, TR2 and ESS TR supply their respective busbars (DC1, DC2, DC ESS):
  • Replace the TIMER [33XE] .
Subtask 24-35-00-810-053-A
C. If the test confirms the fault:
  • Replace the diode module (2420VD).
Subtask 24-35-00-810-054-A
D. If the test confirms the fault:
Subtask 24-35-00-710-051-A
E. Do the test given in Para. 3 and make sure that the normal configuration comes into view.
5. Close-up
Subtask 24-35-00-860-051-A
A. 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 04:26:46 UTC
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