W DOC AIRBUS | TSM A320F

Failure of EPSU 14WL

TASK 33-51-00-810-862-A
Failure of EPSU 14WL

1. Possible Causes
  • EPSU [14WL]
  • signs and lights
  • wiring
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AMM 33-51-00-710-001
Operational Test of the Emergency Lights
ASM 335101
ASM 335104
AMM 33-51-38-000-001
Removal of the Emergency Power-Supply Unit (EPSU)
AMM 33-51-38-400-001
Installation of the Emergency Power-Supply Unit (EPSU)
3. Fault Confirmation
CAUTION: DO NOT USE THE TEACH-IN PROCEDURE AS AN ALTERNATIVE FOR TROUBLESHOOTING. A TEACH-IN PROCEDURE IS NOT A RESET PROCEDURE. BEFORE YOU DO A TEACH-IN PROCEDURE, MAKE SURE THAT YOU CORRECTED ALL FAILURES. IF YOU DO NOT OBEY THIS, FAILURES CAN CAUSE A MALFUNCTION OF THE CABIN EMERGENCY LIGHTING SYSTEM.
Subtask 33-51-00-710-169-A ** ON A/C NOT FOR ALL
A. Do the operational test of the emergency lights with the MCDU AMM 33-51-00-710-001.
4. Fault Isolation
Subtask 33-51-00-810-183-A ** ON A/C NOT FOR ALL
A. If the test gives a different maintenance message, do the trouble shooting procedure related to the maintenance message.
Subtask 33-51-00-810-184-A ** ON A/C NOT FOR ALL
B. If the operational test gives the maintenance message:
EPSU(14WL)MID R:
   (1) If the fault continues:
   (2) If the fault continues:
  • Do a check for a short to ground and repair the wiring if necessary ASM 335101 and ASM 335104:
    from EPSU (14WL) pin E to the connector(s) of the related signs and lights,
    from EPSU (14WL) pin F to the connector(s) of the related signs and lights,
    from EPSU (14WL) pin G to the connector(s) of the related signs and lights,
    from EPSU (14WL) pin H to the connector(s) of the related signs and lights,
    from EPSU (14WL) pin J to the connector(s) of the related signs and lights,
    from EPSU (14WL) pin N to the connector(s) of the related signs and lights,
    from EPSU (14WL) pin R to the connector(s) of the related signs and lights,
    from EPSU (14WL) pin T to the connector(s) of the related signs and lights,
    from EPSU (14WL) pin -B to the connector(s) of the related signs and lights,
    from EPSU (14WL) pin -C to the connector(s) of the related signs and lights,
    from EPSU (14WL) pin -H to the connector(s) of the related signs and lights,
    from EPSU (14WL) pin -J to the connector(s) of the related signs and lights,
  • If you find a short to ground in the wiring, replace the EPSU [14WL] AMM 33-51-38-000-001 and AMM 33-51-38-400-001.
   (3) If the fault continues:
  • Do a check and repair the wiring if necessary ASM 335101:
    from EPSU (14WL) pin -I to DEU-B (300RH4) pin B25,
    from EPSU (14WL) pin -P to DEU-B (300RH4) pin B28,
    from EPSU (14WL) pin X to DEU-B (300RH4) pin B26,
    from EPSU (14WL) pin L to GND,
    from EPSU (14WL) pin M to GND,
    from EPSU (14WL) pin U to GND,
    from EPSU (14WL) pin -R to GND,
    from EPSU (14WL) pin -M to GND.
Subtask 33-51-00-710-170-A ** ON A/C NOT FOR ALL
C. Do the test given in Para. 3.
5. Close-up
Subtask 33-51-00-860-117-A ** ON A/C NOT FOR ALL
A. Put the aircraft back to its initial configuration.
[Rev.8 from Aug 2018] 2026.04.04 04:32:12 UTC
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