W DOC AIRBUS | TSM A320F

EPSU - Emer Overwing Light Fault

TASK 33-51-00-810-809-A
EPSU - Emer Overwing Light Fault

1. Possible Causes
  • LIGHT-FWD EMER, OVERWING [61WL]
  • LIGHT-FWD EMER, OVERWING [60WL]
  • LIGHT-AFT EMER, OVERWING [63WL]
  • LIGHT-AFT EMER, OVERWING [62WL]
  • wiring
  • EPSU [11WL]
  • EPSU [12WL]
2. Job Set-up Information
 A. Fixtures, Tools, Test and Support Equipment
REFERENCE
QTY
DESIGNATION
No specific
2
WARNING NOTICE(S)
 B. 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
AMM 33-51-00-710-001
Operational Test of the Emergency Lights
ASM 335102
AMM 33-51-15-000-001
Removal of the Emergency Overwing Lights
AMM 33-51-15-400-001
Installation of the Emergency Overwing Lights 60WL
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 33-51-00-865-051-A ** ON A/C NOT FOR ALL
A. Make sure that this(these) circuit breaker(s) is(are) closed:
PANELDESIGNATIONFINLOCATION
** ON A/C NOT FOR ALL
49VULIGHTING/EMER LT/CABIN2WLH06
49VULIGHTING/EMER LT/CABIN1WLH05
122VULIGHTING/CABIN/EMER/LT3WLV07
Subtask 33-51-00-860-052-A ** ON A/C NOT FOR ALL
B. Aircraft Maintenance Configuration
   (1) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
   (2) Make sure that the SW-SIGNS/EMER EXIT LT (4WL) switch on the SIGNS panel 25VU is in the OFF position.
   (3) Make sure that all emergency exits are closed.
   (4) Put the WARNING NOTICE(S) in position internally on the emergency exits.
Subtask 33-51-00-710-066-A ** ON A/C NOT FOR ALL
C. Do this test
WARNING: MAKE SURE THAT THE SAFETY PIN IS CORRECTLY INSTALLED IN THE HATCH FRAME IF THE EMERGENCY EXIT HATCH IS REMOVED. THIS PREVENTS AN ACCIDENTAL OPERATION OF THE ESCAPE SLIDE MECHANISM DURING THE MAINTENANCE.
   (1) This test and the subsequent maintenance action are for the LH side of the aircraft. For the RH side use the referenced LRUs as indicated between the parentheses.
ACTION
RESULT
1.At the forward left (right) emergency escape hatch:
  • open the cover of the control handle but do not open the hatch.
On the overwing fuselage:
  • turn the latch pin a quarter turn counterclockwise to the DISARM position.
  • the left (right) emergency overwing lights come on.
  • push and turn the latch pin a quarter turn clockwise to the ARM position.
  • the left (right) emergency overwing lights go off.
  • close the cover of the control handle.
Subtask 33-51-00-710-066-B ** ON A/C NOT FOR ALL
C. Do this test
WARNING: MAKE SURE THAT THE SAFETY PIN IS CORRECTLY INSTALLED IN THE HATCH FRAME IF THE EMERGENCY EXIT HATCH IS REMOVED. THIS PREVENTS AN ACCIDENTAL OPERATION OF THE ESCAPE SLIDE MECHANISM DURING THE MAINTENANCE.
   (1) This test and the subsequent maintenance action are for the LH side of the aircraft. For the RH side use the referenced LRUs as indicated between the parentheses.
ACTION
RESULT
1.At the left (right) emergency escape hatch:
  • open the cover of the control handle but do not open the hatch.
On the overwing fuselage:
  • turn the latch pin a quarter turn counterclockwise to the DISARM position.
  • the left (right) emergency overwing lights come on.
  • push and turn the latch pin a quarter turn clockwise to the ARM position.
  • the left (right) emergency overwing lights go off.
  • close the cover of the control handle.
4. Fault Isolation
Subtask 33-51-00-810-058-A ** ON A/C NOT FOR ALL
A. Maintenance Action
   (1) If the LIGHT-FWD EMER, OVERWING [61WL]
( LIGHT-FWD EMER, OVERWING [60WL] ) does not come on, but the
LIGHT-AFT EMER, OVERWING [63WL]
( LIGHT-AFT EMER, OVERWING [62WL] ) comes on:
     (a) If the fault continues:
  • do a check and repair the wiring between:
    LIGHT-FWD EMER, OVERWING [61WL]
    ( LIGHT-FWD EMER, OVERWING [60WL] ) connector A/B and
    EPSU [11WL]
    ( EPSU [12WL] ) connector A/T,
    LIGHT-FWD EMER, OVERWING [61WL]
    ( LIGHT-FWD EMER, OVERWING [60WL] ) connector A/A and GND,
    LIGHT-FWD EMER, OVERWING [61WL]
    ( LIGHT-FWD EMER, OVERWING [60WL] ) connector A/C and GND ASM 335102.
   (2) If the LIGHT-AFT EMER, OVERWING [63WL]
( LIGHT-AFT EMER, OVERWING [62WL] ) does not come on, but the
LIGHT-FWD EMER, OVERWING [61WL]
( LIGHT-FWD EMER, OVERWING [60WL] ) comes on:
     (a) If the fault continues:
  • do a check and repair the wiring between:
    LIGHT-AFT EMER, OVERWING [63WL]
    ( LIGHT-AFT EMER, OVERWING [62WL] ) connector A/B and
    EPSU [11WL]
    ( EPSU [12WL] ) connector A/F,
    LIGHT-AFT EMER, OVERWING [63WL]
    ( LIGHT-AFT EMER, OVERWING [62WL] ) connector A/A and GND,
    LIGHT-AFT EMER, OVERWING [63WL]
    ( LIGHT-AFT EMER, OVERWING [62WL] ) connector A/C and GND ASM 335102.
   (3) If the LIGHT-FWD EMER, OVERWING [61WL]
( LIGHT-FWD EMER, OVERWING [60WL] ) and the LIGHT-AFT EMER, OVERWING [63WL]
( LIGHT-AFT EMER, OVERWING [62WL] ) do not come on:
     (a) If the fault continues:
  • do a check and repair the wiring between:
    EPSU [11WL]
    ( EPSU [12WL] ) connector A/F and
    LIGHT-AFT EMER, OVERWING [63WL]
    ( LIGHT-AFT EMER, OVERWING [62WL] ) connector A/B,
    EPSU [11WL]
    ( EPSU [12WL] ) connector A/T and LIGHT-FWD EMER, OVERWING [61WL]
    ( LIGHT-FWD EMER, OVERWING [60WL] ) connector A/B,
    LIGHT-FWD EMER, OVERWING [61WL]
    ( LIGHT-FWD EMER, OVERWING [60WL] ) connector A/A and GND,
    LIGHT-FWD EMER, OVERWING [61WL]
    ( LIGHT-FWD EMER, OVERWING [60WL] ) connector A/C and GND,
    LIGHT-AFT EMER, OVERWING [63WL]
    ( LIGHT-AFT EMER, OVERWING [62WL] ) connector A/A and GND,
    LIGHT-AFT EMER, OVERWING [63WL]
    ( LIGHT-AFT EMER, OVERWING [62WL] ) connector A/C and GND ASM 335102.
Subtask 33-51-00-710-067-A ** ON A/C NOT FOR ALL
B. Do the operational test of the emergency lighting to check the correct operation AMM 33-51-00-710-001.
5. Close-up
Subtask 33-51-00-860-053-A ** ON A/C NOT FOR ALL
A. Put the aircraft back to its initial configuration.
   (1) Remove the WARNING NOTICE(S)
   (2) De-energize the aircraft electrical circuits
AMM 24-41-00-862-002.
[Rev.8 from Aug 2018] 2026.04.04 04:32:08 UTC
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