Removal of the AC Service Bus Contactor Module

TASK 24-42-58-000-001-A
Removal of the AC Service Bus Contactor Module

WARNING: MAKE SURE THAT NO AC OR DC POWER IS CONNECTED TO THE AIRCRAFT ELECTRICAL CIRCUITS. THERE IS A RISK OF ELECTROCUTION IF THE AC OR DC POWER STAYS CONNECTED.

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 1M (3 FT)-ADJUSTABLE
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
121AL

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-32-55-000-001-A	Removal of the TR 1 and TR 2 Contactors and the TR 2/AC Service Bus Normal Supply Contactor
TASK 24-42-55-000-001-A	Removal of the Contactors
TASK 24-51-55-000-001-A	Removal of the AC Service Bus Normal Supply Contactor
TASK 25-11-41-000-001-A	Removal of the Third Occupant Seat
AC Service Bus Contactor Module

3. Job Set-up
Subtask 24-42-58-010-050-A ** ON A/C NOT FOR ALL

A. Get Access
(1) Remove the Third Occupant seat (Ref. AMM TASK 25-11-41-000-001).
(2) Remove the front panel of the AC power center 123VU in the cockpit.
(3) Put the ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE in position at the access door 121AL.
(4) Open the access door 121AL.

Subtask 24-42-58-860-050-A ** ON A/C NOT FOR ALL

B. Safety Precautions
(1) Make sure that the external power connector is not connected to the aircraft external power receptacle.
(2) Put a WARNING NOTICE(S) in position on the access door 121AL to tell persons not to connect the external power connector to the aircraft external power receptacle.
(3) In the cockpit, on the ELEC panel 35VU, make sure that these pushbutton switches are released:

BAT 1, BAT 2
APU GEN
GEN 1, GEN 2
EXT PWR.

(4) In the cockpit, put a WARNING NOTICE(S) in position to tell persons not to operate the pushbutton switches on these panels:

21VU (EMER ELEC PWR section)
25VU (APU section)
35VU (ELEC).

4. Procedure
Subtask 24-42-58-020-051-A ** ON A/C NOT FOR ALL

A. Removal of the Contactors Installed on the Contactor Module 20XX
(1) Remove the contactors 12XX and 14XX (Ref. AMM TASK 24-42-55-000-001).
(2) Remove the contactor 14PU (Ref. AMM TASK 24-32-55-000-001).
(3) Remove the contactor 12XN (Ref. AMM TASK 24-51-55-000-001).

Subtask 24-42-58-020-053-A ** ON A/C NOT FOR ALL

B. Removal of the Electrical Components

CAUTION: MAKE MATCH MARKS ON ALL THE ELECTRICAL WIRES BEFORE YOU DISCONNECT THEM. INCORRECT CONNECTION OF WIRES WILL CAUSE DAMAGE TO EQUIPMENT.

(1) Remove the screws (5) and the washers (6).
(2) Disconnect the electrical cables (7).

Subtask 24-42-58-020-050-A ** ON A/C NOT FOR ALL

C. Removal of the Contactor Module 20XX
(1) Remove the protective plugs (2) from the screws (3).
(2) Remove the screws (3).
(3) Remove and discard the locking washers (4).
(4) Remove the contactor module (1).

[Rev.10 from 2021] 2026.04.01 05:49:39 UTC