Failure of the GPCU (Circuit Breaker Open)

TASK 24-40-00-810-802-A
Failure of the GPCU (Circuit Breaker Open)

1. Possible Causes

GPCU [1XG]
wiring

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 24-41-00-740-004	Operational Check of the GPCU via the CFDS
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 24-41-34-000-001	Removal of the Ground Power Control Unit (GPCU)
AMM 24-41-34-400-001	Installation of the Ground Power Control Unit (GPCU)

3. Fault Confirmation
Subtask 24-40-00-860-052-A ** ON A/C NOT FOR ALL

A. Job Set-Up
(1) Aircraft Maintenance Configuration
(a) Energize the aircraft electrical circuits
AMM 24-41-00-861-002

Subtask 24-40-00-740-051-A ** ON A/C NOT FOR ALL

B. Test
Do the operational check of the GPCU with the CFDS AMM 24-41-00-740-004.

4. Fault Isolation
Subtask 24-40-00-810-051-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message CHECK GPCU PIN C2, C/B 4XG, 6XG, 11XG, 12XG WIRING, and the warning AVAIL LIGHT NOT ILLUMINATED:

Do a check of the status of the 7.5 A circuit breaker on the front face of the GPCU.

(1) If the circuit breaker is open:

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

(a) If the fault continues:

Replace the GPCU [1XG] AMM 24-41-34-000-001 and AMM 24-41-34-400-001.

(2) If the circuit breaker is closed:

Do the check of the wiring for short to ground between the pin AC/2 of the GPCU and successively the circuit breakers (4XG), (6XG), (11XG) and (12XG) ASM 244101.

(a) If the wiring is not correct:

Repair the wiring .

(b) If the wiring is correct:

Replace the GPCU [1XG] AMM 24-41-34-000-001 and AMM 24-41-34-400-001.

5. Close-up
Subtask 24-40-00-860-053-A ** ON A/C NOT FOR ALL

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 04:26:52 UTC