Failure of the Neutral Point-Of-Regulation Wiring of the GAPCU

TASK 24-23-00-810-821-A
Failure of the Neutral Point-Of-Regulation Wiring of the GAPCU

1. Possible Causes

wiring
GAPCU [24XG]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 242301
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 24-23-00-869-057-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 24-23-00-810-066-A ** ON A/C NOT FOR ALL

A. If the fault symptom is identified by the CFDS message WRG: GEN NEUTRAL/ GAPCU (24XG) and the upper ECAM-DU warning APU GEN FAULT:

do a check of the Point-Of-Regulation (POR) neutral wiring for an open circuit between the POR neutral connection and pin A/14H of the GAPCU ASM 242301.

(1) If the wiring is not correct:

repair or replace as necessary.

(2) If the wiring is correct:

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

Subtask 24-23-00-860-059-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 04:26:41 UTC