Removal of the Auxiliary Level Sensing Control-Unit (ALSCU)

TASK 28-46-35-000-001-A
Removal of the Auxiliary Level Sensing Control-Unit (ALSCU)

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

ZONE: 120
FIN: 60QJ ** ON A/C NOT FOR ALL

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

REFERENCE	QTY	DESIGNATION
No specific	1	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
120	AVIONICS COMPARTMENT
811

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 28-00-00-910-001-A	Fuel Safety Procedures
Auxiliary Level Sensing Control-Unit (ALSCU)

3. Job Set-up
Subtask 28-46-35-861-050-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Obey the fuel safety procedures (Ref. AMM TASK 28-00-00-910-001).
(2) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(3) Put the WARNING NOTICE(S) on the panels that follow, to tell persons not to operate the fuel system:

Refuel/Defuel panels 800VU and 801VU.
Fuel control panel 40VU
Additional Center Tank (ACT) control panel 28VU.

Subtask 28-46-35-865-050-A ** ON A/C NOT FOR ALL

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	ALSCU SPLY	66QJ	B10
121VU	FUEL/ALSCU/HI LEVEL/SPLY	64QJ	K21
121VU	FUEL/ALSCU/SPLY	65QJ	K20

Subtask 28-46-35-010-050-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put an ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position below access door 811.
(2) Open access door 811.

4. Procedure
Subtask 28-46-35-020-050-A ** ON A/C NOT FOR ALL

A. Removal of the ALSCU

Auxiliary Level Sensing Control-Unit (ALSCU) ** ON A/C NOT FOR ALL

(1) Loosen and lower the knurled nut (4).

CAUTION: DO NOT TOUCH THE CONNECTOR PINS OR OTHER CONDUCTORS ON THE COMPONENT DURING THE PROCEDURE. IF YOU TOUCH THESE CONDUCTORS, ELECTROSTATIC DISCHARGE CAN CAUSE DAMAGE TO COMPONENT.

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.

(2) Carefully pull the ALSCU (1) out of the rack (2) to disconnect electrical connectors (3).
(3) Remove the ALSCU (1) from its rack (2).
(4) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.

[Rev.10 from 2021] 2026.04.02 06:18:17 UTC