Unwanted ELEC AC BUS 1 FAULT Warning

TASK 24-50-00-810-806-A
Unwanted ELEC AC BUS 1 FAULT Warning

1. Possible Causes

SDAC-1 [1WV1]
SDAC-2 [1WV2]
RELAY-BUS 1XP CTL [15XC]
wiring
RELAY-BUS 1XP CTL (20XN1)
C/B-ELEC/AC/BUS1/CTL [17XN1]

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 242501
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 245102
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 24-50-00-860-058-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 24-50-00-710-060-A

B. Test
(1) Do this 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 AC 1 busbar indication shown in amber.
	On the upper ECAM DU: The ELEC AC BUS 1 FAULT warning comes into view.

4. Fault Isolation
Subtask 24-50-00-810-055-A

A. If the test confirms the fault:

Do a check of the status of the ELEC/AC/BUS1/CTL circuit breaker (17XN1).

(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.
Replace RELAY-BUS 1XP CTL [15XC] .

a If the fault continues:

Do a check for continuity and repair the wiring between:
. Pin A/X1 of the BUS 1XP control relay (15XC) and the ELEC/AC/BUS1/CTL circuit breaker (17XN1)
. Pin A/X2 of the BUS 1XP control relay (15XC) and the ground, ASM 242501
. Pin A/X1 of the BUS 1XP control relay (20XN1) and the first branch point, ASM 245102.
Do a check for a short to ground and for a short circuit of the wiring between:
. Pins AA/5D of SDAC 1 and SDAC 2 and the pin A/B2 of the bus 1XP control relay (15XC), ASM 242501.

(2) If the circuit breaker is open:

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

(a) If the fault continues:

Replace RELAY-BUS 1XP CTL [15XC] .

1 If the fault continues:

Replace RELAY-BUS 1XP CTL (20XN1).

2 If the fault continues:

Replace C/B-ELEC/AC/BUS1/CTL [17XN1] .

Subtask 24-50-00-710-061-A

B. 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 24-50-00-860-059-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 04:26:56 UTC