Failure of the Battery of EPSU 15WL

TASK 33-51-00-810-879-A
Failure of the Battery of EPSU 15WL

1. Possible Causes

battery of EPSU 15WL
EPSU [15WL]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 33-51-00-710-001	Operational Test of the Emergency Lights
AMM 33-51-00-710-003	Check of the Battery Capacity
AMM 33-51-38-000-001	Removal of the Emergency Power-Supply Unit (EPSU)
AMM 33-51-38-000-002	Removal of the Battery of the Emergency Power-Supply Unit
AMM 33-51-38-400-001	Installation of the Emergency Power-Supply Unit (EPSU)
AMM 33-51-38-400-002	Installation of the Battery of the Emergency Power-Supply Unit

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 33-51-00-710-203-A ** ON A/C NOT FOR ALL

A. Do the operational test 'Check Battery Capacity' with the MCDU AMM 33-51-00-710-003.

4. Fault Isolation
Subtask 33-51-00-810-218-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 33-51-00-810-219-A ** ON A/C NOT FOR ALL

B. If the operational test gives the maintenance message:
(1) BAT/EPSU(15WL)MID L:

Do the operational test of the emergency lights with the MCDU AMM 33-51-00-710-001.

Subtask 33-51-00-810-220-A ** ON A/C NOT FOR ALL

C. If the test gives the maintenance message:
(1) BAT/EPSU(15WL)MID L:

Replace the battery of EPSU 15WL AMM 33-51-38-000-002 and AMM 33-51-38-400-002.

(a) If the fault continues:

Replace the EPSU [15WL] AMM 33-51-38-000-001 and AMM 33-51-38-400-001.

Subtask 33-51-00-710-204-A ** ON A/C NOT FOR ALL

D. Do the test given in Para. 3.

5. Close-up
Subtask 33-51-00-860-134-A ** ON A/C NOT FOR ALL

A. Put the aircraft back to its initial configuration.

[Rev.8 from Aug 2018] 2026.04.04 04:32:13 UTC