Installation of the Power Supply Unit

TASK 33-48-37-400-001-A
Installation of the Power Supply Unit

FIN: 4LV

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Consumable Materials

REFERENCE	DESIGNATION
(Material No.04QAB2)	Coating_- Flexible Structure
No specific	lockwire - corrosion resistant steel 0.6mm (0.24 in.) dia.

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
191HB

C. Referenced Information

REFERENCE	DESIGNATION
TASK 20-28-00-912-802-A	Electrical Bonding - General Maintenance Procedure
TASK 33-48-00-710-001-A	Operational Test of the Anti-Collision Lighting
TASK 53-35-13-400-002-A	Installation of the Quick-Release Access Panels on the Belly Fairing Structure
Power Supply Unit 4LV

3. Job Set-up
Subtask 33-48-37-860-051-A

A. Aircraft Maintenance Configuration
(1) Make sure that switch 2LV BEACON ON-OFF on overhead panel 25VU is in the OFF position.
(2) Make sure that access panel 191HB at the belly fairing is removed.

Subtask 33-48-37-865-051-A

B. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
122VU	LIGHTING/EXT LT/BEACON/LOWER	5LV	U03

4. Procedure
Subtask 33-48-37-420-050-A

A. Installation of the Power Supply Unit
(1) Clean the component interfaces and the adjacent area.
(2) Do an inspection of the component interfaces and the adjacent area.
(3) Put the power supply unit (1) in position on the fuselage.
(4) Install the washers (3) and the screws (4) and (6).
(5) Apply a thin layer of Coating_- Flexible Structure (Material No.04QAB2) on the screw (6) (Ref. AMM TASK 20-28-00-912-802).
(6) Remove the CAP-BLANKING from each electrical connector and receptacle.
(7) Connect the electrical connectors (2) and (5) to the power supply unit (1).

WARNING: USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.

CAUTION: MAKE SURE THAT THE ELECTRICAL CONNECTORS ARE CLEAN BEFORE YOU DISCONNECT OR CONNECT THEM. CONTAMINATION ON THE ELECTRICAL CONNECTORS CAN CAUSE DAMAGE TO EQUIPMENT.

(8) Safety the electrical connector (5) with lockwire - corrosion resistant steel 0.6mm (0.24 in.) dia.

NOTE: It is not necessary to safety the connector with the lockwire, if it is a self-locking connector.

Subtask 33-48-37-865-052-A

B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
122VU	LIGHTING/EXT LT/BEACON/LOWER	5LV	U03

Subtask 33-48-37-710-050-A

C. Do an operational test of the lower beacon/strobe light 6LV (Ref. AMM TASK 33-48-00-710-001).

5. Close-up
Subtask 33-48-37-410-050-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install access panel 191HB on the belly fairing (Ref. AMM TASK 53-35-13-400-002).

[Rev.10 from 2021] 2026.04.01 00:56:44 UTC