Short Circuits of the Feeders between the APU Generator and the APU GLC

TASK 24-20-00-810-945-A
Short Circuits of the Feeders between the APU Generator and the APU GLC

1. Possible Causes

feeders
GEN-APU [8XS]
GAPCU [24XG]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 242301
AMM 24-23-51-000-001	Removal of the APU Generator
AMM 24-23-51-400-001	Installation of the APU Generator
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
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 24-20-00-869-096-A ** ON A/C NOT FOR ALL

A. Test
Not applicable.

NOTE: As the APU GEN was set to OFF because of a true failure, the fault confirmation is not necessary.

4. Fault Isolation
Subtask 24-20-00-810-164-D ** ON A/C NOT FOR ALL

A. If the fault symptom is identified by the CFDS message WRG: GEN APU FEEDER and the upper ECAM-DU warning APU GEN FAULT:

Do a check of the feeders ASM 242301 for a short circuit or a short to airframe between:
. Terminal T1 of the APU generator (8XS) and pin 7 of the APU/EXT power contactor module (29XN)
. Terminal T2 of the APU generator (8XS) and pin 8 of the APU/EXT power contactor module (29XN)
. Terminal T3 of the APU generator (8XS) and pin 9 of the APU/EXT power contactor module (29XN).

(1) If the wiring is not correct:

Repair or replace the feeders as necessary.

(2) If the wiring is correct:

Replace the GEN-APU [8XS] AMM 24-23-51-000-001 and AMM 24-23-51-400-001.

(a) If the fault continues:

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

Subtask 24-20-00-860-166-A ** ON A/C NOT FOR ALL

B. Make sure that the aircraft electrical circuits operate correctly in APU configuration.
(1) Energize the aircraft electrical circuits from the APU AMM 24-41-00-861-002.
(2) Let the APU generator operate for five minutes to make sure that it operates correctly.
(3) De-energize the aircraft electrical circuits from the APU AMM 24-41-00-862-002.

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