Removal of the GCU-1(2)

TASK 24-22-34-000-001-A
Removal of the GCU-1(2)

CAUTION: USE ONLY THE GROUND SERVICE NETWORK TO SUPPLY THE AIRCRAFT WITH AC AND DC POWER. YOU CAN CAUSE DAMAGE TO THE EQUIPMENT DURING ITS REMOVAL/ INSTALLATION IF THE RELATED NETWORK IS NOT ISOLATED.

ZONE: 121
FIN: 1XU1
FIN: 1XU2

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE
No specific	AR	CAP - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
121	AVIONICS COMPARTMENT
811

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
Generator Control Unit 1(2) GCU-1(2) ** ON A/C NOT FOR ALL
Generator Control Unit 1(2) GCU-1(2) ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 24-22-34-860-050-A

A. Aircraft Maintenance Configuration
(1) Energize the Ground Service network (Ref. AMM TASK 24-42-00-861-001).
(2) In the cockpit, put a WARNING NOTICE(S) to tell persons not to operate the pushbutton switches (ENG MASTER 1(2)) on the pylon panel 115VU (ENG panel)

Subtask 24-22-34-865-052-A

B. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 1XU1 (GCU1)
122VU	ELEC/GCU/1	2XU1	T26
FOR FIN: 1XU2 (GCU2)
122VU	ELEC/GCU/2	2XU2	T27

Subtask 24-22-34-010-052-A

C. Get Access
(1) Put an ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE at the access door 811 of the avionics compartment.
(2) Open the access door 811.

4. Procedure
Subtask 24-22-34-020-052-A

A. Removal of the GCU
(1) Loosen the 2 knurled nuts (1).
(2) Lower the 2 knurled nuts (1) to disengage the 2 studs (2).
(3) Carefully pull the handle (3) of the GCU (4) until the GCU is disconnected from the rack receptacle (5).
(4) Remove the GCU from the rack (6).
(5) Put CAP - BLANKING on the rack receptacle (5) and on the GCU connector.

[Rev.10 from 2021] 2026.03.31 23:22:10 UTC