Installation of the AC Service Bus Contactor Module

TASK 24-42-58-400-001-A
Installation 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. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
4	LOCKING WASHERS	AIPC 24-42-08-04-020
4	LOCKING WASHERS	AIPC 24-42-88-04-020

D. Referenced Information

REFERENCE	DESIGNATION
TASK 24-32-55-400-001-A	Installation of the TR 1 and TR 2 Contactors and the TR 2/AC Service Bus Normal Supply Contactor
TASK 24-42-55-400-001-A	Installation of the Contactors
TASK 24-51-55-400-001-A	Installation of the AC Service Bus Normal Supply Contactor
TASK 25-11-41-000-001-A	Removal of the Third Occupant Seat
TASK 25-11-41-400-001-A	Installation of the Third Occupant Seat
AC Service Bus Contactor Module

3. Job Set-up
Subtask 24-42-58-010-051-A ** ON A/C NOT FOR ALL

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

Subtask 24-42-58-860-051-A ** ON A/C NOT FOR ALL

B. Aircraft Maintenance Configuration
(1) Make sure that the external power connector is not connected to the aircraft external power receptacle.
(2) Make sure that the WARNING NOTICE(S) is in position at 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, make sure that the WARNING NOTICE(S) is 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 24-42-58-420-050-A ** ON A/C NOT FOR ALL

A. Installation of the Contactor Module 20XX
(1) Put the contactor module (1) on its support.
(2) Install the new AIPC 24-42-08-04-020 LOCKING WASHERS (4) or AIPC 24-42-88-04-020 LOCKING WASHERS (4) and the screws (3).
(3) Tighten the screws (3).
(4) Install the protective plugs (2) on the screws (3).

Subtask 24-42-58-420-051-A ** ON A/C NOT FOR ALL

B. Installation of the Electrical Components

CAUTION: REFER TO THE MATCH MARKS MADE DURING THE REMOVAL WHEN YOU CONNECT THE ELECTRICAL WIRES. INCORRECT CONNECTION OF THE WIRES WILL CAUSE DAMAGE TO EQUIPMENT.

(1) Put the electrical cables (7) in position on the contactor module (1).
(2) Install the washers (6) and the screws (5).
(3) Tighten the screws (5).

Subtask 24-42-58-420-052-A ** ON A/C NOT FOR ALL

C. Installation of the Contactors on the Module 20XX
(1) Install the contactors 12XX and 14XX (Ref. AMM TASK 24-42-55-400-001).
(2) Install the contactor 14PU (Ref. AMM TASK 24-32-55-400-001).
(3) Install the contactor 12XN (Ref. AMM TASK 24-51-55-400-001).

5. Close-up
Subtask 24-42-58-410-050-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the front panel of the AC power center 123VU.
(3) Install the Third Occupant seat (Ref. AMM TASK 25-11-41-400-001).
(4) Remove the WARNING NOTICE(S).
(5) Close the access door 121AL.
(6) Remove the access platform(s).

[Rev.10 from 2021] 2026.03.31 23:24:36 UTC