Failure of the AC BUS2 with External Power in Use

TASK 24-50-00-810-810-A
Failure of the AC BUS2 with External Power in Use

1. Possible Causes

BTC-2 [11XU2]
wiring
RELAY-EPC AUX CTL [5XG]
RELAY-GLC 2 AUX CTL [4XU2]
GLC-2 [9XU2]
RELAY-SMOKE [30XU2]
C/B-ELEC/EXT PWR/CTL [11XG]

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 242203
AMM 24-22-55-000-001	Removal of the Contactors
AMM 24-22-55-400-002	Installation of the Contactors
ASM 242302
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 244101
AMM 31-60-00-860-001	EIS Start Procedure

3. Fault Confirmation
Subtask 24-50-00-860-066-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 24-50-00-710-068-A

B. Test
Do this test:

ACTION	RESULT
1.On the ELEC panel 35VU: release the GEN1 and GEN2 pushbutton switches.	On the ELEC panel 35VU: the OFF legends of the GEN1 and GEN2 pushbutton switches come on. On the upper ECAM display unit: the ELEC AC BUS 2 FAULT warning comes into view.

4. Fault Isolation
Subtask 24-50-00-865-054-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
122VU	ELEC/EXT PWR/CTL	11XG	X29

Subtask 24-50-00-810-059-A ** ON A/C NOT FOR ALL

B. If the test confirms the fault:

Do a check of the status of the circuit breaker (11XG)

(1) If the circuit breaker is closed:

Replace the BTC-2 [11XU2] AMM 24-22-55-000-001 and AMM 24-22-55-400-002.

(a) If the fault continues:

Do a check and repair the wiring between the pin B/5 of the BTC2 and the pin AA/9C of the GCU2 ASM 242203.

(b) If the fault continues:

Do a check for 28VDC:

1 If there is no 28VDC at the pin A/D2 of the relay (5XG):

Replace the RELAY-EPC AUX CTL [5XG] .

a If the fault continues:

Repair the wiring between the circuit breaker ELEC/EXT PWR CTL (11XG) and the relay (5XG) ASM 244101.

2 If there is no 28VDC at the pin A/A2 of the relay (4XU2):

Replace the RELAY-GLC 2 AUX CTL [4XU2] .

a If the fault continues:

Repair the wiring between the pin A/D2 of the relay (5XG) and the pin A/A3 of the relay (4XU2) ASM 242203 and ASM 242302.

3 If there is no 28VDC at the pin B/6 of the GLC2 (9XU2):

Replace the GLC-2 [9XU2] AMM 24-22-55-000-001 and AMM 24-22-55-400-002.

a If the fault continues:

Repair the wiring between the pin A/A2 of the relay (4XU2) and the pin B/8 of the GLC2 (9XU2) ASM 242203.

4 If there is no 28VDC at the pin B/3 of the BTC2 (11XU2):

Replace the RELAY-SMOKE [30XU2] .

a If the fault continues:

Do a check and repair the wiring between:
. the pin B/6 of the GLC2 (9XU2) and the relay (30XU2) ASM 242203
. the relay (30XU2) and the pin B/3 of the BTC2 (11XU2) ASM 242203.

(2) If the circuit breaker is open:

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

(a) If the fault continues:

Replace the C/B-ELEC/EXT PWR/CTL [11XG] .

Subtask 24-50-00-810-059-B ** ON A/C NOT FOR ALL

B. If the test confirms the fault:

Do a check of the status of the circuit breaker (11XG).

(1) If the circuit breaker is closed:

Replace BTC-2 [11XU2] AMM 24-22-55-000-001 and AMM 24-22-55-400-002.

(a) If the fault continues:

Do a check and repair the wiring between pin B/5 of BTC2 and pin AA/9C of GCU2 ASM 242203.

(b) If the fault continues:

Do a check for 28VDC:

1 If there is no 28VDC at pin A/D2 of the relay (5XG):

Replace RELAY-EPC AUX CTL [5XG] .

a If the fault continues:

Repair the wiring between the circuit breaker ELEC/EXT PWR CTL (11XG) and the relay (5XG) ASM 244101.

2 If there is no 28VDC at pin A/A2 of the relay (4XU2):

Replace RELAY-GLC 2 AUX CTL [4XU2] .

a If the fault continues:

Repair the wiring between pin A/D2 of the relay (5XG) and pin A/A3 of the relay (4XU2) ASM 242203 and ASM 242302.

3 If there is no 28VDC at pin B/22 of GLC2 (9XU2):

Replace GLC-2 [9XU2] AMM 24-22-55-000-001 and AMM 24-22-55-400-002.

a If the fault continues:

Repair the wiring between pin A/A2 of the relay (4XU2) and pin B/24 of GLC2 (9XU2) ASM 242203.

4 If there is no 28VDC at pin B/3 of BTC2 (11XU2):

Replace RELAY-SMOKE [30XU2] .

a If the fault continues:

Do a check and repair the wiring between:
. Pin B/22 of the GLC2 (9XU2) and the relay (30XU2) ASM 242203
. The relay (30XU2) and pin B/3 of BTC2 (11XU2) ASM 242203.

(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-ELEC/EXT PWR/CTL [11XG] .

Subtask 24-50-00-810-059-C ** ON A/C NOT FOR ALL

B. If the test confirms the fault:

Do a check of the status of the circuit breaker (11XG).

(1) If the circuit breaker is closed:

Replace BTC-2 [11XU2] AMM 24-22-55-000-001 and AMM 24-22-55-400-002.

(a) If the fault continues:

Do a check and repair the wiring between pin B/5 of BTC2 and pin AA/9A of GCU2 ASM 242203.

(b) If the fault continues:

Do a check for 28VDC:

1 If there is no 28VDC at pin A/D2 of the relay (5XG):

Replace RELAY-EPC AUX CTL [5XG] .

a If the fault continues:

Repair the wiring between the circuit breaker ELEC/EXT PWR CTL (11XG) and the relay (5XG) ASM 244101.

2 If there is no 28VDC at pin A/A2 of the relay (4XU2):

Replace RELAY-GLC 2 AUX CTL [4XU2] .

a If the fault continues:

Repair the wiring between pin A/D2 of the relay (5XG) and pin A/A3 of the relay (4XU2) ASM 242203 and ASM 242302.

3 If there is no 28VDC at pin B/22 of the GLC2 (9XU2):

Replace GLC-2 [9XU2] AMM 24-22-55-000-001 and AMM 24-22-55-400-002.

a If the fault continues:

Repair the wiring between pin A/A2 of the relay (4XU2) and pin B/24 of GLC2 (9XU2) ASM 242203.

4 If there is no 28VDC at pin B/3 of BTC2 (11XU2):

Replace RELAY-SMOKE [30XU2] .

a If the fault continues:

Do a check and repair the wiring between:
. Pin B/22 of GLC2 (9XU2) and the relay (30XU2) ASM 242203
. The relay (30XU2) and pin B/3 of BTC2 (11XU2) ASM 242203.

(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-ELEC/EXT PWR/CTL [11XG] .

Subtask 24-50-00-710-069-A

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

ACTION	RESULT
On the ECAM control panel: push the ELEC key to get the ELEC page.	On the lower ECAM display unit: the normal configuration comes into view.

5. Close-up
Subtask 24-50-00-860-067-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.
(a) De-energize the aircraft electrical circuits
AMM 24-41-00-862-002.

[Rev.8 from Aug 2018] 2026.04.04 04:26:56 UTC