ACT 1 HI LVL Manual TEST

TASK 28-46-00-810-827-A
ACT 1 HI LVL Manual TEST

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

WARNING: WHEN YOU DO WORK ON THE FUEL SYSTEM WIRING, YOU MUST USE TEST EQUIPMENT THAT IS APPROVED (REFER TO INTERNATIONAL OR NATIONAL SPECIFICATIONS FOR INTRINSICALLY SAFE TEST EQUIPMENT: EN50020, UL913 OR EQUIVALENT). TEST EQUIPMENT THAT IS NOT APPROVED CAN CAUSE FIRE OR AN EXPLOSION.

1. Possible Causes

FLSCU 3 [47QJ]
CTL PNL-REFUEL/DEFUEL (ACT) [801VU]
C/B-ACT1/REFUEL & SPLY [33QU]
RELAY-HI LVL IND CTL, ACT 1 [56QJ]
aircraft wiring
PROBE-FQI NO 2, ACT1 [66QT1]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 28-46-00-810-823-A	LEFT HI LVL Manual TEST
TSM TASK 28-46-00-810-824-A	RIGHT HI LVL Manual TEST
TSM TASK 28-46-00-810-825-A	CTR HI LVL Manual TEST
AMM 12-11-28-650-004	Pressure Refuel with Manual Control
AMM 28-25-00-650-001	Pressure Defuel
AMM 28-25-00-869-001	Fuel Transfer
AMM 28-25-58-000-001	Removal of the Refuel Panel
AMM 28-25-58-400-001	Installation of the Refuel Panel
AMM 28-42-24-000-001	Removal of the Fuel Quantity Probe of the ACT
AMM 28-42-24-400-001	Installation of the Fuel Quantity Probe of the ACT
AMM 28-46-00-710-001	Test of the Tank High-Level Sensing-System
ASM 284601
AMM 28-46-34-000-001	Removal of the Fuel-Level Sensing Control-Unit (FLSCU)
AMM 28-46-34-400-001	Installation of the Fuel-Level Sensing Control-Unit (FLSCU)
AMM 31-60-00-860-001	EIS Start Procedure

3. Fault Confirmation
Subtask 28-46-00-865-067-A ** ON A/C NOT FOR ALL

A. Table of the circuit breakers referred to in this procedure:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	ACT1/REFUEL & SPLY	33QU	L29

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

B. Test
(1) Do the Operational Test of the Tank High Level Sensing System AMM 28-46-00-710-001.

NOTE: More data can be got from the:

Description and Operation (D and O) section of the Aircraft Maintenance Manual (AMM), Chap. 28-46-00, the Fuel Level Sensing System (FLSS)
Trouble Shooting Manual (TSM) - Task Supporting Data (Ref. P. Block 301)
Aircraft Schematic Manual (ASM) ASM 284601.

The FQIC does not do a BITE test of the FLSCU-3 or the related ACT FLSS sensors.

The FQIC does not monitor the FLSCU-3 or the related ACT FLSS sensors:

state (sensor wet or dry)
status/condition (serviceable/unserviceable).

More Trouble-shooting data can be got from the:

HI LVL Indicator, ACT (49QJ) located on the Refuel Panel ACT (801VU), used with the Fuel Level Sensors Operating (Changeover) Values (Ref. P. Block 301)

NOTE: OPTIONAL TESTING:
If a PSDA321-1 Test Set is available, a check can be made before a decision is made to go into or close up a fuel tank. The Test Set lets a GO/NOGO check to be made of the tank mounted components and wiring from the tank wall connectors.

4. Fault Isolation
Subtask 28-46-00-810-076-F ** ON A/C NOT FOR ALL

A. Procedure
(1) If any of the HI LVL indicator lamps on the Refuel Panel (800VU) fail to change state, from off to on, or from on to off, Trouble-shoot those indicators as follows:

LEFT HI LVL Manual TEST (Ref. TSM TASK 28-46-00-810-823)
RIGHT HI LVL Manual TEST (Ref. TSM TASK 28-46-00-810-824)
CTR HI LVL Manual TEST (Ref. TSM TASK 28-46-00-810-825).

(2) If the ACT 1 HI LVL Indicator lamp on the Panel Assy-Refuel, ACT (801VU) fails to change state, from off to on, or from on to off:

interchange the FLSCU-3 (47QJ) with the FLSCU-1 (7QJ) AMM 28-46-34-000-001 and AMM 28-46-34-400-001.

(3) Do the test given in Para. 3.B.
(4) If the ACT 1 HI LVL Indicator light changes state during the test:
(a) Install the original FLSCU-1 in the FLSCU-1 position.
(b) Replace the FLSCU 3 [47QJ] AMM 28-46-34-000-001 and AMM 28-46-34-400-001.
(5) Do the test given in Para. 3.B.
(6) If the fault continues:

replace the CTL PNL-REFUEL/DEFUEL (ACT) [801VU] AMM 28-25-58-000-001 and AMM 28-25-58-400-001.

NOTE: If due to airline operational conditions it is not possible to replace the ACT REFUEL-PANEL (801VU) and internal Trouble-shooting is required, go to Step (22).

(7) If the fault continues:
(a) Do a check of ASM 284601 and replace, if necessary:
1 The C/B-ACT1/REFUEL & SPLY [33QU] .
2 The RELAY-HI LVL IND CTL, ACT 1 [56QJ] .

NOTE: The purpose of RELAY-HI LVL IND, ACT 1 (56QJ) and associated circuitry is to control the ACT 1 high level indicator light.
When the ACT 1 is not installed, C/B-REFUEL SUPPLY, ACT 1 (33QU) is opened, safetied and tagged.
This action stops the RELAY-56QJ from energizing and therfore inhibits the ACT 1 high level lamp from illuminating (permanently on) during a refuel. This is done by making sure that the ground input to the FLSCU-3 high level channel (LS3) output relay is removed when the aircraft is operated in this configuration.

(b) Do a check of the aircraft wiring ASM 284601 between:

the FLSCU-3 rack connector AA, pin 1B and the C/B-FUEL/HI/LVL/SPLY (1QJ), terminal 2 (121VU) (28VDC supply line)
the REFUEL-PANEL (800VU), free connector 4024VC-A, pin R and the FLSCU-3 rack connector AA, pin 13B (HI LVL SYSTEM TEST line)
the ACT REFUEL-PANEL (801VU), free connector 4067VC-A, pin V and the FLSCU-3 rack connector AA, pin 7A (LS3 HI LVL TEST output line)
the FLSCU-3 rack connector AA, pin 6A and the RELAY-CTL HI LVL IND, ACT 1 (56QJ), terminal A2 (ground i/p for LS3 TEST o/p line)
the RELAY-CTL HI LVL IND, ACT 1 (56QJ), terminal A1 and the ground DC1
the RELAY-CTL HI LVL IND, ACT 1 (56QJ), terminal X2 and the ground DC1
the RELAY-CTL HI LVL IND, ACT 1 (56QJ), terminal X1 and the C/B-REFUEL SUPPLY, ACT 1 (33QU).

(c) Repair all the unserviceable wiring and connectors.
(d) Do the test given in Para. 3.B.
(8) Set the Electronic Centralized Aircraft Monitoring (ECAM) system to on AMM 31-60-00-860-001.
(a) On the ECAM Control panel 11VU, push the FUEL pushbutton switch in.
(b) Make sure that the FUEL System Display is shown on the lower ECAM DU.
(9) Make a note of the ACT 1 fuel quantity shown on the Fuel System Display.
(10) Make sure that the ACT 1 contains not more than 2,000 kg (4,400 lb) of fuel:

defuel/transfer fuel if necessary AMM 28-25-00-650-001 or AMM 28-25-00-869-001.

NOTE: This is to make sure that the ACT 1 high level sensor is dry.

(11) With the High Level Light TEST switch (2QJ) in the center (neutral) position, the ACT 1, HI LVL indicator (49QJ) (lamp) must be OFF.
(12) If the ACT 1, HI LVL indicator (49QJ) (lamp):
(a) Is OFF, go to step (13).
(b) Is ON, go to step (16).

NOTE: The high level sensor has failed WET. With this fault it is not possible to do an auto or manual pressure refuel as the refuel valve will not be permitted to open.

(13) Do a Manual Refuel of the ACT 1 only, to a minimum of 2,390 kg (5,260 lb) AMM 12-11-28-650-004.

NOTE: This is to make sure that the ACT 1 high level sensor is wet.

(14) With the High Level Light TEST switch (2QJ) in the center (neutral) position, the ACT 1, HI LVL indicator (49QJ) (lamp) must be ON.
(15) If the ACT 1, HI LVL indicator (49QJ) (lamp):
(a) Is OFF, go to step (16).

NOTE: The high level sensor has failed DRY. With this fault the fuel high level protection system will not operate with the risk of a possible fuel spillage.

(b) Is ON, no further Trouble-shooting steps are necessary.
(16) Test Equipment.

(a) If there is:

approved test equipment available, go to Step (17)
no approved test equipment, go to Step (18).

(17) Do a resistance check ASM 284601 of the high level sensor (part of PROBE-FQI No 2, ACT 1 (66QT1)) at the tank wall connector 66QT1-A, (803VU) between pins G and F.

NOTE: The sensor status (wet or dry) and fuel/air temperature will have an effect on the resistance value.

(a) If the resistance is between 330 and 480 ohms:

go to Step (18).

(b) If the resistance is not between 330 and 480 ohms:

go to Step (21).

(18) Do a check of the aircraft wiring ASM 284601 between:

the FLSCU-3 rack connector AB, pin 10A and the ACT aircraft to tank break 7618VC1, pin 11 (sensor input line - H)
the FLSCU-3 rack connector AB, pin 10B and the ACT aircraft to tank break 7618VC1, pin 12 (sensor input line - L)
the ACT aircraft to tank break free connector 7618VC1-A, pin 11 and the tank unit free connector 66QT1-A, pin G (sensor input line - H)
the ACT aircraft to tank break free connector 7618VC1-A, pin 12 and the tank unit free connector 66QT1-A, pin F (sensor input line - L).

(19) Repair all the unserviceable wiring and connectors.
(20) Do the test given in Para. 3.B.
(21) If the fault continues:

replace the PROBE-FQI NO 2, ACT1 [66QT1] AMM 28-42-24-000-001 and AMM 28-42-24-400-001.

(22) ACT REFUEL-PANEL (801VU) Internal Trouble-shooting
(a) Do a check and repair as necessary the ACT REFUEL PANEL (801VU) wiring ASM 284601:

between the connector 4067VC, pin V and the IND-HI LVL ACT (49QJ) terminal I.

(b) Install the ACT REFUEL-PANEL (801VU), AMM 28-25-58-400-001.
(c) Do the test given in Para. 3.B.

[Rev.8 from Aug 2018] 2026.04.04 04:39:39 UTC