Unwanted DC ESS BUS FAULT Warning

TASK 24-60-00-810-816-A
Unwanted DC ESS BUS FAULT Warning

1. Possible Causes

SDAC-1 [1WV1]
SDAC-2 [1WV2]
wiring
C/B-SDAC/1 AND 2/28VDC/ESS BUS [12WV]

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 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 24-60-00-860-076-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 24-60-00-710-079-A

B. Test

ACTION	RESULT
1.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 ESS busbar indication shown in amber.
	On the upper ECAM DU: The ELEC DC ESS BUS FAULT warning comes into view.

4. Fault Isolation
Subtask 24-60-00-865-061-A

A. Table of the circuit breakers used in this procedure:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	SDAC/1 AND 2/28VDC/ESS BUS	12WV	F05

Subtask 24-60-00-810-069-A

B. If the fault continues:

Do a check of the status of the SDAC1&SDAC2/28VDC/ESS BUS circuit breaker (12WV):

(1) If the circuit breaker is closed:

Remove SDAC1 AMM 31-55-34-000-001.

(a) If the fault does not continue:

Replace SDAC-1 [1WV1] AMM 31-55-34-400-001.

(b) If the fault continues:

Install SDAC1 AMM 31-55-34-400-001.
Remove SDAC2 AMM 31-55-34-000-001.

1 If the fault does not continue:

Replace SDAC-2 [1WV2] AMM 31-55-34-400-001.

2 If the fault continues:

Install SDAC2 AMM 31-55-34-400-001.

a If the fault continues:

Do a check and repair the wiring from the 401PP busbar to the first branch point, through the circuit breaker (12WV) ASM 315408.

(2) If the circuit breaker is open:

Do the procedure (Ref. TSM TASK 24-00-00-810-803).

(a) If the fault continues:

Replace C/B-SDAC/1 AND 2/28VDC/ESS BUS [12WV] .

Subtask 24-60-00-710-080-A

C. Do this test to make sure that the system operates correctly:

ACTION	RESULT
1.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 24-60-00-860-077-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 04:26:59 UTC