Test of the Additional Center Tank (ACT) High-Level-Sensing System

TASK 28-46-00-710-002-A
Test of the Additional Center Tank (ACT) High-Level-Sensing System

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

WARNING: PUT THE SAFETY DEVICES AND THE WARNING NOTICES IN POSITION BEFORE YOU START A TASK ON OR NEAR:

THE FLIGHT CONTROLS
THE FLIGHT CONTROL SURFACES
THE LANDING GEAR AND THE RELATED DOORS
COMPONENTS THAT MOVE.

MOVEMENT OF COMPONENTS CAN KILL OR CAUSE INJURY TO PERSONS AND/OR CAN CAUSE DAMAGE TO THE EQUIPMENT.

ZONE: 120
ZONE: 192
ZONE: 211

1. Reason for the Job
To test at the refuel/defuel panels 800VU and 801VU the:

HI LVL lights (for the wing tanks, the center tank and the ACT(s))
High level sensors in the fuel tanks(for wing tanks 17QJ1 (17QJ2) and 28QJ1 (28QJ2), center tank 5QJ and ACTs 61QJX (62QJX) (X will be defined by the number of the ACT))
FLSCU 7QJ (9QJ) (high level channels)
ALSCU 60QJ (high level channels).

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 2M (6 FT)
No specific	AR	SAFETY BARRIER(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
120	AVIONICS COMPARTMENT
192	AIR CONDITIONING COMPT AND FAIRINGS
211	COCKPIT
192MB, 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 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 28-00-00-910-001-A	Fuel Safety Procedures

3. Job Set-up
Subtask 28-46-00-941-058-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) Obey the fuel safety procedures (Ref. AMM TASK 28-00-00-910-001).
(2) As necessary, use the applicable SAFETY BARRIERS, specified by the operator's instructions and your local regulations.

Subtask 28-46-00-860-059-A ** ON A/C NOT FOR ALL

B. Aircraft Maintenance Configuration

WARNING: MAKE SURE THAT ALL THE CIRCUITS IN MAINTENANCE ARE ISOLATED BEFORE YOU SUPPLY ELECTRICAL POWER TO THE AIRCRAFT. UNWANTED ELECTRICAL POWER CAN BE DANGEROUS.

(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).

Subtask 28-46-00-010-057-B ** ON A/C NOT FOR ALL

C. Get Access
(1) Get access to ACT high-level-sensor-selector-switches 72QJ1, 72QJ2 (if ACT AFT2 is installed) and 72QJ4 (if ACT FWD is installed) in the avionics compartment (on panel 102VU):
(a) Put an ACCESS PLATFORM 2M (6 FT) in position at access door 811.
(b) Open access door 811.
(2) Get access to refuel/defuel control-panels 800VU and 801VU:
(a) Open access door 192MB.

4. Procedure
Subtask 28-46-00-710-058-A ** ON A/C NOT FOR ALL

A. Test of the HI LVL Lights (lamp check)
(1) Do this test:

ACTION	RESULT
1.On panels 800VU and 801VU:
Set the REFUEL VALVES switches to the NORM position. Set the MODE SELECT switch to the OFF position.
2.On panel 800VU:	On panels 800VU and 801VU:
Hold the TEST switch in the LTS position.	If the HI LVL lights were off they come on. If the HI LVL lights were on they stay on.
Release the TEST switch.	If the HI LVL lights came on they go off. If the HI LVL lights were on they stay on.

Subtask 28-46-00-710-059-B ** ON A/C NOT FOR ALL

B. High-Level-Sensing System Test

NOTE: The HI LVL lights of the ACT(s) that are not installed will not operate in the tests that follow.

NOTE: Quantity of fuel in each tank to be equal to the subsequent results of the high level test. You can do a check (for each tank) on FUEL QTY indicator 6QT and ACT refuel/defuel-panel 801VU to find which of these conditions is applicable:

Condition 1. The quantity of fuel is less than the high level.
Condition 2. The quantity of fuel is at or more than the high level.

(1) In the avionics compartment, on panel 102VU:
(a) Record the position of ACT high-level-sensor selector-switches 72QJ1, 72QJ2 (if ACT AFT2 is installed) and 72QJ4 (if ACT FWD is installed).
(b) Set ACT high-level-sensor selector-switches 72QJ1, 72QJ2 (if ACT AFT2 is installed) and 72QJ4 (if ACT FWD is installed) to the NORM position.
(2) Do this test:

ACTION	RESULT
1.On panel 800VU:	On panel 800VU and 801VU:
Hold the TEST switch in the HI LVL position	For condition 1 (see note): The HI LVL light for each applicable tank comes on
	For condition 2 (see note): The HI LVL light for each applicable tank goes off
Release the TEST switch.	For condition 1 (see note): The HI LVL light for each applicable tank goes off
	For condition 2 (see note): The HI LVL light for each applicable tank comes on.

(3) In the avionics compartment, on panel 102VU:
(a) Set ACT high-level-sensor selector-switches 72QJ1, 72QJ2 (if ACT AFT2 is installed) and 72QJ4 (if ACT FWD is installed) in the SPARE position.
(4) Do the test from step (2) again.
(5) In the avionics compartment, on panel 102VU:
(a) Set ACT high-level-sensor selector-switches 72QJ1, 72QJ2 (if ACT AFT2 installed) and 72QJ4 (if ACT FWD is installed) back to their initial positions.

5. Close-up
Subtask 28-46-00-860-060-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

Subtask 28-46-00-410-056-A ** ON A/C NOT FOR ALL

B. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close access door 192MB.
(3) Close access door 811.

Subtask 28-46-00-942-058-A ** ON A/C NOT FOR ALL

C. Removal of Equipment
(1) If installed, remove the safety barriers.
(2) Remove the access platform(s).
(3) Remove the ground support and maintenance equipment, the special and standard tools and all other items.

[Rev.10 from 2021] 2026.04.02 07:03:14 UTC