DOC AIRBUS | TSM A320FFuel - ACT Auto Transfer System - Pressurization Fault
TASK 28-28-00-810-839-A
Fuel - ACT Auto Transfer System - Pressurization Fault
A. Fixtures, Tools, Test and Support Equipment
B. Referenced Information
3. Fault Confirmation
Subtask 28-28-00-710-075-B ** ON A/C NOT FOR ALL
Subtask 28-28-00-810-094-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:28:52 UTC
Fuel - ACT Auto Transfer System - Pressurization Fault
WARNING:
OBEY THE FUEL SAFETY PROCEDURES.
1. Possible Causes- VALVE-AIR SHUTOFF, ACT [168QM]
- VALVE-PRESSURE REDUCING, ACT1 [171QM]
- ACTUATOR-AIR SHUTOFF VALVE, ACT [3QH]
- Relay-panel 802VU
- RELAY-PRESSURIZATION CONTROL, ACT [28QH]
- RELAY-POWER SUPPLY SWITCH [39QU]
- aircraft wiring
- ACTUATOR-VENT VALVE, ACT1 [4QH1]
167QM - ACTUATOR-VENT VALVE, ACT2 [4QH2]
- VALVE-VENT, ACT2 [167QM2]
- ACT 2
- ACT 1
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | MULTIMETER - STANDARD |
| REFERENCE | DESIGNATION |
|---|---|
| TSM TASK 28-13-00-810-801-A | Fuel - Leak Shows at Drain Mast |
| TSM TASK 28-28-00-810-801-A | Fuel Pumps - ACT Manual Transfer Pump 1QH System Malfunction |
| TSM TASK 28-28-00-810-801-A-01 | Fuel Pumps - ACT Manual Transfer Pump 1QH System Malfunction (802VU ACT Relay Testbox) |
| TSM TASK 28-28-00-810-802-A | Fuel - ACT 1 Manual Transfer Failure (On The Ground) |
| TSM TASK 28-28-00-810-802-A-01 | Fuel - ACT 1 Manual Transfer Failure (On The Ground) (802VU ACT Relay Testbox) |
| TSM TASK 28-28-00-810-806-A | Fuel - ACT Transfer System Flag/Symbol Failure |
| TSM TASK 28-28-00-810-807-A | Fuel - ACT 2 Sequence Failure |
| TSM TASK 28-28-00-810-807-A-01 | Fuel - ACT 2 Sequence Failure (802VU ACT Relay Testbox) |
| ESPM 2053210 | |
| AMM 25-55-11-000-002 | Removal of the Ceiling Panels in the Aft Cargo-Compartment - FR47/FR59 |
| AMM 27-80-00-866-005 | Retracting the Slats on the Ground |
| AMM 28-11-27-000-001 | Removal of the Additional Center Tank (ACT) |
| AMM 28-11-27-400-001 | Installation of the Additional Center Tank (ACT) |
| AMM 28-28-00-710-001 | Operational Check of the ACT Manual Transfer System |
| AMM 28-28-00-710-004 | Operational Test of the ACT Automatic Transfer System |
| AMM 28-28-00-720-001 | Functional Test of the ACT Pressure Reducing Valve |
| ASM 282801 | |
| AWM 282802 | |
| ASM 282803 | |
| ASM 282804 | |
| AWM 282804 | |
| AMM 28-28-35-000-001 | Removal of the ACT Vent Shut-off Valve (167QM) |
| AMM 28-28-35-400-001 | Installation of the ACT Vent Shut-off Valve (167QM) |
| AMM 28-28-36-000-001 | Removal of the ACT Air Shut-Off Valve |
| AMM 28-28-36-400-001 | Installation of the ACT Air Shut-Off Valve |
| AMM 28-28-42-000-001 | Removal of the ACT Pressure Reducing Valve |
| AMM 28-28-42-400-001 | Installation of the ACT Pressure Reducing Valve |
| AMM 28-28-55-000-001 | Removal of the ACT Vent Shut-off Valve Actuator (4QH) |
| AMM 28-28-55-400-001 | Installation of the ACT Vent Shut-off Valve Actuator (4QH) |
| AMM 28-28-56-000-001 | Removal of the ACT Air Shut-Off Valve Actuator |
| AMM 28-28-56-400-001 | Installation of the ACT Air Shut-Off Valve Actuator |
| AMM 32-69-00-860-001 | Simulation of Flight (With Aircraft on Ground) |
Subtask 28-28-00-710-075-B ** ON A/C NOT FOR ALL
A. General
You must read all of this paragraph before you start the test procedure (work steps) in Para. 3.B.
(1) Introduction
This sub-paragraph contains:
The ACT fuel automatic transfer system is powered by a controlled air bleed from the cabin pressurization and is therefore not effective on the ground or at low altitude. The system becomes operational after a ten minute delay. This is a function of the relay-22QH, when the two signals that follow are AND gated together in the relay-panel 802VU:
The ACT air pressure system becomes operational when the airshut-off valve opens and the ACT 1 and ACT 2 vent valves close.
If the slats are positioned at less than 16 degrees, the transfer valve and the sequence related ACT inlet valve open to give a fuel flow to the center tank.
The differential air pressure between the cabin air and the air pressure outside of the aircraft causes the fuel to transfer.
The ACT automatic transfer symbol (an open triangle) given on the ECAM - FUEL system page shows that the transfer valve and the sequence related inlet valve are in the correct positions for a transfer (Ref. ESLB 31-67-28). This eliminates the need to troubleshoot the fuel-flow valve positions.
(b) Useful Data References
You can get more data about the ACT Transfer System from the:
Get as much data (as possible) about the malfunction and (if used) the subsequent steps of the abnormal procedure from:
This sub-paragraph gives a list of (and describes) the prerequisite tests, the functional test and the post functional test options that are used as routing (a guide) into the troubleshooting procedures in Para. 4.
They are relatively quick and can save time.
(a) Operational Test of the ACT Manual Transfer System AMM 28-28-00-710-001
This is a quick procedure to show if the actuators, transfer valve and inlet valves can be made to operate. It also shows that a ground supplied by the center tank high level sensor system is serviceable when the sensor is dry.
During a manual transfer, when the aircraft is on the ground, the center-tank high-level sensor channel supplies a safety feature to prevent (stop) a fuel spillage. If fuel is transfered into a full center tank it will overflow out through the center tank vent and go overboard through the NACA vent. In normal operation, if the the center tank is full and the high level sensor is wet, the ground supplied by the high-level sensor channel is removed and the transfer of ACT fuel is stopped.
In auto transfer, this same ground output from the FLSCU-1 (7QJ) is one of two inputs required to start the 10 minute time delay sequence of the relay 22QH.
You are advised to do the ACT manual transfer test before the basic leak test. A fuel leak will show if the fuel system has been in operation rather than a system that has not been used.
(b) Basic Leak Tests (Ref. TSM TASK 28-13-00-810-801)
This procedure will show if there is a leak below the fuel level (past and present levels).
(c) Leak Test Pressurized as given in the Service Bulletin (Ref. SB A320-28-1090)
This is a leak check using a Ground Pressure Generator (GPG) to test the system with pressure. It will show a leak above or below the fuel level (example, fuel transfer pipe-line or vent pipe-line).
(d) ACT Air Supply Test AMM 28-28-00-720-001
This check uss a GPG is to test the pressure reducing valve and the related air-line between the test connections T1 and T2.
(e) Functional Test AMM 28-28-00-710-004
The functional test of the ACT automatic transfer system
Helps you identify if the malfunction is in the avionic, fuel or air sub-systems.
Subtask 28-28-00-710-076-A ** ON A/C NOT FOR ALL You must read all of this paragraph before you start the test procedure (work steps) in Para. 3.B.
(1) Introduction
This sub-paragraph contains:
- a short description of the operation of the ACT air pressurization system
- a list of useful references to get more data
- advice for the troubleshooter.
The ACT fuel automatic transfer system is powered by a controlled air bleed from the cabin pressurization and is therefore not effective on the ground or at low altitude. The system becomes operational after a ten minute delay. This is a function of the relay-22QH, when the two signals that follow are AND gated together in the relay-panel 802VU:
- the aircraft has taken off (in flight) - from LGCIU-1 (5GA1) 32-31-00
- the center tank high level sensor is dry - from FLSCU-1 (7QJ) 28-46-00.
The ACT air pressure system becomes operational when the airshut-off valve opens and the ACT 1 and ACT 2 vent valves close.
If the slats are positioned at less than 16 degrees, the transfer valve and the sequence related ACT inlet valve open to give a fuel flow to the center tank.
The differential air pressure between the cabin air and the air pressure outside of the aircraft causes the fuel to transfer.
The ACT automatic transfer symbol (an open triangle) given on the ECAM - FUEL system page shows that the transfer valve and the sequence related inlet valve are in the correct positions for a transfer (Ref. ESLB 31-67-28). This eliminates the need to troubleshoot the fuel-flow valve positions.
(b) Useful Data References
You can get more data about the ACT Transfer System from the:
- Aircraft Maintenance Manual (AMM), Page Block 1
Chap. 28-28-00, the Additional Center Tank (ACT) Transfer System
Chap. 28-46-00, the Fuel Level Sensing System (FLSS)
Chap. 27-81-00, the Slats Electrical Control and Monitoring
Chap. 32-69-00, Landing Gear - Bite - Aircraft Schematic Manual (ASM), ACT XFR System
Inlet Valve ASM 282801
Transfer Valve ASM 282803
Vent Valve ASM 282804
High Level Refuel Control ASM 282801
FLSS, Low Level Indication AWM 282802.
Get as much data (as possible) about the malfunction and (if used) the subsequent steps of the abnormal procedure from:
- the aircraft technical log
- the flight crew.
NOTE: The ACT system cannot pressurize, to give an ACT automatic fuel transfer, if there is:
(2) The Tests Used During This Procedure - a fuel leak
- an air leak
- no (cabin or test rig) air pressure to cause the fuel to be transferred.
This sub-paragraph gives a list of (and describes) the prerequisite tests, the functional test and the post functional test options that are used as routing (a guide) into the troubleshooting procedures in Para. 4.
They are relatively quick and can save time.
(a) Operational Test of the ACT Manual Transfer System AMM 28-28-00-710-001
This is a quick procedure to show if the actuators, transfer valve and inlet valves can be made to operate. It also shows that a ground supplied by the center tank high level sensor system is serviceable when the sensor is dry.
During a manual transfer, when the aircraft is on the ground, the center-tank high-level sensor channel supplies a safety feature to prevent (stop) a fuel spillage. If fuel is transfered into a full center tank it will overflow out through the center tank vent and go overboard through the NACA vent. In normal operation, if the the center tank is full and the high level sensor is wet, the ground supplied by the high-level sensor channel is removed and the transfer of ACT fuel is stopped.
In auto transfer, this same ground output from the FLSCU-1 (7QJ) is one of two inputs required to start the 10 minute time delay sequence of the relay 22QH.
You are advised to do the ACT manual transfer test before the basic leak test. A fuel leak will show if the fuel system has been in operation rather than a system that has not been used.
(b) Basic Leak Tests (Ref. TSM TASK 28-13-00-810-801)
This procedure will show if there is a leak below the fuel level (past and present levels).
(c) Leak Test Pressurized as given in the Service Bulletin (Ref. SB A320-28-1090)
This is a leak check using a Ground Pressure Generator (GPG) to test the system with pressure. It will show a leak above or below the fuel level (example, fuel transfer pipe-line or vent pipe-line).
(d) ACT Air Supply Test AMM 28-28-00-720-001
This check uss a GPG is to test the pressure reducing valve and the related air-line between the test connections T1 and T2.
(e) Functional Test AMM 28-28-00-710-004
The functional test of the ACT automatic transfer system
NOTE: Make sure that before the test is started the fuel load is configured correctly. If the fuel load is not configured correctly the XRF FAULT warning can be given (triggered). When the XFR FAULT warning is given it causes the ACT transfer symbol to be removed from the ECAM - FUEL page. The ACT transfer symbol is a primary indication during this procedure and for its related fault symptoms. The ACT transfer symbol shows that the transfer valve and the sequence related ACT inlet valve are in the open (correct) positions for a fuel transfer. This elimimates the need to trouble shoot the actuator/valve positions.
(f) Post Functional Test Options Helps you identify if the malfunction is in the avionic, fuel or air sub-systems.
B. Operational Test of the ACT Manual Transfer System
(1) Do the Operational Test of the ACT Manual Transfer System AMM 28-28-00-710-001.
(a) If the ACT manual transfer system:
1 Is serviceable, do Para. C.
2 Is unserviceable:
a Do the applicable trouble-shooting as follows:
b Do Para. C.
Subtask 28-28-00-710-077-A ** ON A/C NOT FOR ALL (1) Do the Operational Test of the ACT Manual Transfer System AMM 28-28-00-710-001.
(a) If the ACT manual transfer system:
1 Is serviceable, do Para. C.
2 Is unserviceable:
a Do the applicable trouble-shooting as follows:
b Do Para. C.
C. Basic Leak Tests
(1) Do a check of the three leak monitors (Ref. TSM TASK 28-13-00-810-801).
(a) If you find no fuel in the leak monitors:
1 Do Para. D.
(b) If you find fuel in a leak monitor:
1 Do the related trouble-shooting (Ref. TSM TASK 28-13-00-810-801).
2 Do Para. D.
Subtask 28-28-00-710-078-B ** ON A/C NOT FOR ALL (1) Do a check of the three leak monitors (Ref. TSM TASK 28-13-00-810-801).
(a) If you find no fuel in the leak monitors:
1 Do Para. D.
(b) If you find fuel in a leak monitor:
1 Do the related trouble-shooting (Ref. TSM TASK 28-13-00-810-801).
2 Do Para. D.
D. Leak Test Pressurized
(1) Do the Leak Test of the ACT Fuel/Vent System and Pressurization System as given in the Service Bulletin (Ref. SB A320-28-1090).
(2) If you find (any) fuel, vent or pressurization leaks, repair/replace all unserviceable items as necessary.
(3) Do Para. E.
Subtask 28-28-00-710-079-C ** ON A/C NOT FOR ALL (1) Do the Leak Test of the ACT Fuel/Vent System and Pressurization System as given in the Service Bulletin (Ref. SB A320-28-1090).
(2) If you find (any) fuel, vent or pressurization leaks, repair/replace all unserviceable items as necessary.
(3) Do Para. E.
E. ACT Air Supply Test
(1) Do the Functional Test of the Pressure Reducing Valve AMM 28-28-00-720-001.
(a) If you find the system does not pressurize:
1 Make sure that you have followed the procedure correctly.
2 Make sure that the pressure blanking plug installed to the aircraft air supply line makes a sealed connection.
3 If necessary:
a Replace the VALVE-AIR SHUTOFF, ACT [168QM] AMM 28-28-36-000-001 and AMM 28-28-36-400-001.
b Replace the VALVE-PRESSURE REDUCING, ACT1 [171QM] AMM 28-28-42-000-001 and AMM 28-28-42-400-001.
c Replace all the unserviceable air pipes and connections.
(b) If you find the system does pressurize:
1 Make sure that the hose connections between the aircraft air supply points and the ACT 1 and the ACT 2 are free from blockage, twists, and kinks.
(2) Keep the gages installed and the GPG connected.
(3) Do Para. F.
Subtask 28-28-00-710-080-A ** ON A/C NOT FOR ALL (1) Do the Functional Test of the Pressure Reducing Valve AMM 28-28-00-720-001.
(a) If you find the system does not pressurize:
1 Make sure that you have followed the procedure correctly.
2 Make sure that the pressure blanking plug installed to the aircraft air supply line makes a sealed connection.
3 If necessary:
a Replace the VALVE-AIR SHUTOFF, ACT [168QM] AMM 28-28-36-000-001 and AMM 28-28-36-400-001.
b Replace the VALVE-PRESSURE REDUCING, ACT1 [171QM] AMM 28-28-42-000-001 and AMM 28-28-42-400-001.
c Replace all the unserviceable air pipes and connections.
(b) If you find the system does pressurize:
1 Make sure that the hose connections between the aircraft air supply points and the ACT 1 and the ACT 2 are free from blockage, twists, and kinks.
(2) Keep the gages installed and the GPG connected.
(3) Do Para. F.
F. Functional Test
It is important to make sure that there are no (known/obvious) fuel, vent, or pressurization leaks in the ACT system before you do the test that follows.
(1) Do the subtasks that follow of the Operational Test of the ACT Automatic Transfer System AMM 28-28-00-710-004 but do not start the test.
(a) The Job Set-up.
(b) The Preparation for the Test.
(2) Read Para. 3.G.
(3) Start the test as follows:
(a) Start the air supply.
(b) Set to simulated flight mode to start the ACT automatic transfer sequence.
(4) Do Para. 3.G. at the same time as the test.
Subtask 28-28-00-710-081-A ** ON A/C NOT FOR ALL It is important to make sure that there are no (known/obvious) fuel, vent, or pressurization leaks in the ACT system before you do the test that follows.
(1) Do the subtasks that follow of the Operational Test of the ACT Automatic Transfer System AMM 28-28-00-710-004 but do not start the test.
(a) The Job Set-up.
(b) The Preparation for the Test.
(2) Read Para. 3.G.
(3) Start the test as follows:
(a) Start the air supply.
(b) Set to simulated flight mode to start the ACT automatic transfer sequence.
(4) Do Para. 3.G. at the same time as the test.
G. Post Functional Test Options
(1) Wait for more than ten minutes from the time simulated flight mode was selected.
(2) During the ten minute wait get access to the actuator, air shut-off valve (3QH) AMM 28-28-56-000-001 through the maintenance cover in the AFT cargo compartment, ceiling panel 151CC AMM 25-55-11-000-002.
(3) Do a check of the actuator, air shut-off valve (3QH) see/feel indicator to see if it is open or closed.
(4) If the actuator, air shut-off valve (3QH):
(a) Is open, do step (4).
(b) Is closed:
1 Do Para. 4.A. - Actuator, Air Shut-off Valve - 3QH failed to open after ten minutes.
2 If the fault continues:
a Do Para. 4.B. - 802VU - R and I, if a serviceable spare relay-panel 802VU is available
b Do Para. 4.C. - 802VU - internal troubleshooting for the air shut-off valve fails to open, if a serviceable spare relay-panel 802VU is not available.
(5) Do a check of the pressure gage at test point T2 to see if the system has pressurized.
(6) If the pressure gage at test point T2:
(a) Is pressurized:
1 Do a check of the air supply hoses, between the aircraft and ACTs.
2 Make sure that they are free from kinks, twists or blockage.
3 Do the Test of the ACT Automatic Transfer System AMM 28-28-00-710-004.
(b) Is not pressurized:
1 Do Para. 4.D.
(7) If the ACT transfer system flag/symbol was not shown in manual and/or automatic modes of operation but fuel transferred correctly, do ACT Transfer System Flag/Symbol Failure (Ref. TSM TASK 28-28-00-810-806).
4. Fault Isolation(1) Wait for more than ten minutes from the time simulated flight mode was selected.
(2) During the ten minute wait get access to the actuator, air shut-off valve (3QH) AMM 28-28-56-000-001 through the maintenance cover in the AFT cargo compartment, ceiling panel 151CC AMM 25-55-11-000-002.
(3) Do a check of the actuator, air shut-off valve (3QH) see/feel indicator to see if it is open or closed.
(4) If the actuator, air shut-off valve (3QH):
(a) Is open, do step (4).
(b) Is closed:
1 Do Para. 4.A. - Actuator, Air Shut-off Valve - 3QH failed to open after ten minutes.
2 If the fault continues:
a Do Para. 4.B. - 802VU - R and I, if a serviceable spare relay-panel 802VU is available
b Do Para. 4.C. - 802VU - internal troubleshooting for the air shut-off valve fails to open, if a serviceable spare relay-panel 802VU is not available.
(5) Do a check of the pressure gage at test point T2 to see if the system has pressurized.
(6) If the pressure gage at test point T2:
(a) Is pressurized:
1 Do a check of the air supply hoses, between the aircraft and ACTs.
2 Make sure that they are free from kinks, twists or blockage.
3 Do the Test of the ACT Automatic Transfer System AMM 28-28-00-710-004.
(b) Is not pressurized:
1 Do Para. 4.D.
(7) If the ACT transfer system flag/symbol was not shown in manual and/or automatic modes of operation but fuel transferred correctly, do ACT Transfer System Flag/Symbol Failure (Ref. TSM TASK 28-28-00-810-806).
Subtask 28-28-00-810-094-A ** ON A/C NOT FOR ALL
A. Actuator, Air Shut-off Valve (3QH) failed to open after 10 minutes
(1) Make sure that:
(a) The P/BSW-FUEL/ACT/AUTO (24QH) is released out.
(b) The aircraft stays in the simulated flight mode AMM 32-69-00-860-001.
(c) 10 minutes have lapsed.
(d) The simulated flight mode has not timed out.
(2) Do the Actuator Air Shutoff Valve (3QH) automatic transfer trouble-shooting as follows:
(a) Disconnect the AIR SHUTOFF VALVE (3QH) free connector 3QH-A.
(b) Do a test, with a MULTIMETER - STANDARD, at the free connector 3QH-A, between the pins A (+ve) and E (-ve) ASM 282804 to see if 28VDC is available.
1 If the voltage is correct, do a check of and replace, if necessary:
a The ACTUATOR-AIR SHUTOFF VALVE, ACT [3QH] AMM 28-28-56-000-001 and AMM 28-28-56-400-001.
b The VALVE-AIR SHUTOFF, ACT [168QM] AMM 28-28-36-000-001 and AMM 28-28-36-400-001.
2 If the voltage is not correct, do a test, with a multimeter, at the 802VU test connector 4068VC, between the pins Y (+ve) and a ground (-ve) ASM 282804 to see if 28VDC is available.
a If the voltage is not correct, continue as directed in Para. 3.G. step (4)(b)2_.
b If the voltage is correct, do a check of the aircraft wiring ASM 282804 between:
d Do the Operational Test of the ACT Transfer System AMM 28-28-00-710-004.
Subtask 28-28-00-810-098-A ** ON A/C NOT FOR ALL (1) Make sure that:
(a) The P/BSW-FUEL/ACT/AUTO (24QH) is released out.
(b) The aircraft stays in the simulated flight mode AMM 32-69-00-860-001.
(c) 10 minutes have lapsed.
(d) The simulated flight mode has not timed out.
(2) Do the Actuator Air Shutoff Valve (3QH) automatic transfer trouble-shooting as follows:
(a) Disconnect the AIR SHUTOFF VALVE (3QH) free connector 3QH-A.
(b) Do a test, with a MULTIMETER - STANDARD, at the free connector 3QH-A, between the pins A (+ve) and E (-ve) ASM 282804 to see if 28VDC is available.
1 If the voltage is correct, do a check of and replace, if necessary:
a The ACTUATOR-AIR SHUTOFF VALVE, ACT [3QH] AMM 28-28-56-000-001 and AMM 28-28-56-400-001.
b The VALVE-AIR SHUTOFF, ACT [168QM] AMM 28-28-36-000-001 and AMM 28-28-36-400-001.
2 If the voltage is not correct, do a test, with a multimeter, at the 802VU test connector 4068VC, between the pins Y (+ve) and a ground (-ve) ASM 282804 to see if 28VDC is available.
a If the voltage is not correct, continue as directed in Para. 3.G. step (4)(b)2_.
b If the voltage is correct, do a check of the aircraft wiring ASM 282804 between:
- the actuator air shutoff valve connector 3QH-A, pin A and relay-panel 802VU connector 4065VC-A, pin X
- the actuator air shutoff valve connector 3QH-A, pin E and ground point DC1.
d Do the Operational Test of the ACT Transfer System AMM 28-28-00-710-004.
B. Procedure - Relay-panel 802VU (R and I) if a serviceable spare is available
(1) Temporarily replace the relay-panel 802VU with a serviceable item.
(3) If the ACT automatic transfer:
(a) Is serviceable:
1 Complete the installation of the serviceable spare relay-panel 802VU.
(b) Is not serviceable:
1 Install the initial relay-panel 802VU.
2 Do Para. 3.F. and Para. 3.G. again.
Subtask 28-28-00-810-100-B ** ON A/C NOT FOR ALL (1) Temporarily replace the relay-panel 802VU with a serviceable item.
NOTE: The step (1) has been included because it quickly lets you see the condition (serviceable or unserviceable) of the original relay-panel 802VU.
(2) Do the Operational Test of the ACT Automatic Transfer System AMM 28-28-00-710-004. (3) If the ACT automatic transfer:
(a) Is serviceable:
1 Complete the installation of the serviceable spare relay-panel 802VU.
(b) Is not serviceable:
1 Install the initial relay-panel 802VU.
2 Do Para. 3.F. and Para. 3.G. again.
C. Procedure - Relay Panel 802VU Internal Troubleshooting
Air Shut-off Valve Does Not Open After 10 Minutes
(1) Make sure that the free connector 4065VC-A is connected to the relay-panel 802VU
(2) Do the steps that follow.
This will let the ACT AUTO transfer sequence start.
(a) Make sure that the P/BSW-FUEL/ACT/AUTO (24QH) is released out.
(b) Make sure that the ACT 1 contains more than 250 kg (560 lb) of fuel.
(c) Make sure that the ACT 2 contains more than 250 kg (560 lb) of fuel.
(d) Make sure that the center tank contains less than 6000 kg (13220 lb) of fuel.
(e) Make sure that the slats are retracted AMM 27-80-00-866-005.
(f) Close the Refuel Panel door.
(g) Do the Simulation of Flight with the Aircraft on the Ground AMM 32-69-00-860-001.
(3) Do a test, with a multimeter, at the RELAY-PANEL (802VU) test connector 4068VC, between the pin Y and a suitable ground ASM 282804 to see if 28VDC is available.
1 Remove the connector 4065VC-A from the relay-panel 802VU.
2 Examine the connector and receptical 4065VC, pin/socket X for in-correct mating, damage and/or bent pin.
3 Repair or replace any unserviceable items ESPM 2053210.
4 Do the Operational Test of the ACT Automatic Transfer System AMM 28-28-00-710-004.
5 If the fault continues, do the wiring checks (in step (3)(b)2_, lines 1 and 2) of the connections between the test point Y and the connector 4065VC, pin X.
(b) If the 28VDC is not available at pin Y, continue as follows:
1 Do a check of ASM 282804 and replace, if necessary:
2 Do a check of the RELAY-PANEL (802VU) wiring ASM 282804 between the connector to relay and relay to relay lines, as shown in the table that follows:
b Do the Operational Test of the ACT Transfer System AMM 28-28-00-710-004.
Subtask 28-28-00-810-097-B ** ON A/C NOT FOR ALL Air Shut-off Valve Does Not Open After 10 Minutes
(1) Make sure that the free connector 4065VC-A is connected to the relay-panel 802VU
(2) Do the steps that follow.
This will let the ACT AUTO transfer sequence start.
(a) Make sure that the P/BSW-FUEL/ACT/AUTO (24QH) is released out.
(b) Make sure that the ACT 1 contains more than 250 kg (560 lb) of fuel.
(c) Make sure that the ACT 2 contains more than 250 kg (560 lb) of fuel.
(d) Make sure that the center tank contains less than 6000 kg (13220 lb) of fuel.
(e) Make sure that the slats are retracted AMM 27-80-00-866-005.
(f) Close the Refuel Panel door.
(g) Do the Simulation of Flight with the Aircraft on the Ground AMM 32-69-00-860-001.
(3) Do a test, with a multimeter, at the RELAY-PANEL (802VU) test connector 4068VC, between the pin Y and a suitable ground ASM 282804 to see if 28VDC is available.
NOTE: This step is to check the 28VDC open command to the actuator air shut-off valve, when RELAY-28QH is de-energized.
(a) If the 28VDC is available at pin Y: 1 Remove the connector 4065VC-A from the relay-panel 802VU.
2 Examine the connector and receptical 4065VC, pin/socket X for in-correct mating, damage and/or bent pin.
3 Repair or replace any unserviceable items ESPM 2053210.
4 Do the Operational Test of the ACT Automatic Transfer System AMM 28-28-00-710-004.
5 If the fault continues, do the wiring checks (in step (3)(b)2_, lines 1 and 2) of the connections between the test point Y and the connector 4065VC, pin X.
(b) If the 28VDC is not available at pin Y, continue as follows:
1 Do a check of ASM 282804 and replace, if necessary:
2 Do a check of the RELAY-PANEL (802VU) wiring ASM 282804 between the connector to relay and relay to relay lines, as shown in the table that follows:
NOTE: The circuit connections shown in the table are abbreviated, for example:
a Repair all unserviceable wiring and connectors ESPM 2053210. - the connector 4068VC, pin Y is shown as 4068VC-Y
- the RELAY-PRESS CTL, ACT (28QH), terminal A3 is shown as RL 28QH-A3.
| ----------------------------------------------------------------------------- |
| ! CONNECTOR-PIN ! RELAY-TERMINAL TO RELAY-TERMINAL ! CONNECTOR-PIN ! |
| !-----------------------------------------------------------------------------! |
| ! 4068VC-Y ----------------------------------- RL 28QH-A3 ! |
| ! RL 28QH-A3 ---------------------------------- 4065VC-X ! |
| ! RL 28QH-A2 ----------------- RL 39QU-C2 ! |
| ! RL 39QU-C3 ---------------------------------- 4065VC-<G ! |
| ----------------------------------------------------------------------------- |
b Do the Operational Test of the ACT Transfer System AMM 28-28-00-710-004.
D. No pressure shown at the pressure gage at Test Point 2.
(1) Get access AMM 28-28-55-000-001 to the:
(a) The P/BSW-FUEL/ACT/AUTO (24QH) is released out.
(b) The aircraft stays in the simulated flight mode AMM 32-69-00-860-001.
(c) 10 minutes have lapsed.
(d) The simulated flight mode has not timed out.
(3) Do a check of the:
(6) If only the ACT 2 actuator, vent valve 4QH2 is open, do step (9).
(7) If the ACT 1 and ACT 2, actuator, vent valves 4QH1 and 4QH2 see/feel indicators show open:
(a) Make sure that the Actuator Air Shut-off Valve connector 3QH-A is correctly connected to the 3QH receptacle.
1 Do a check of and replace, if necessary, the ACTUATOR-AIR SHUTOFF VALVE, ACT [3QH] AMM 28-28-56-000-001 and AMM 28-28-56-400-001.
b Do the Operational Test of the ACT Automatic Transfer System AMM 28-28-00-710-004.
(8) If only the ACT 1 actuator, vent valve 4QH1 see/feel indicator shows open:
(a) Disconnect the ACTUATOR VENT VALVE, ACT 1 (4QH1) connector 4QH1-A.
(b) Do a test, with a multimeter, at the connector 4QH1-A, between the pins B (+ve) and E (-ve) ASM 282804 to see if 28VDC is available.
1 If the voltage is correct do a check of and replace, if necessary:
a The ACTUATOR-VENT VALVE, ACT1 [4QH1] AMM 28-28-55-000-001 and AMM 28-28-55-400-001.
b The167QM AMM 28-28-35-000-001 and AMM 28-28-35-400-001.
2 If the voltage is not correct do a check of the aircraft wiring AWM 282804 between:
b Do the Operational Test of the ACT Automatic Transfer System AMM 28-28-00-710-004.
c If the fault continues (no pressure at pressure gage T2, when the actuator air shut-off and vent valves are in the correct positions) do step (10).
(9) If only the ACT 2 actuator, vent valve 4QH2 see/feel indicator shows open:
(a) Disconnect the ACTUATOR VENT VALVE, ACT 2 (4QH2) connector 4QH2-A.
(b) Do a test, with a multimeter, at the connector 4QH2-A, between the pins B (+ve) and E (-ve) ASM 282804 to see if 28VDC is available.
1 If the voltage is correct do a check of and replace, if necessary:
a The ACTUATOR-VENT VALVE, ACT2 [4QH2] AMM 28-28-55-000-001 and AMM 28-28-55-400-001.
b The VALVE-VENT, ACT2 [167QM2] AMM 28-28-35-000-001 and AMM 28-28-35-400-001.
2 If the voltage is not correct do a check of the aircraft wiring AWM 282804 between:
b Do the Operational Test of the ACT Transfer System AMM 28-28-00-710-004.
c If the fault continues (no pressure at pressure gage T2, when the actuator air shut-off and vent valves are in the correct position) do step (10).
(10) If the ACT 1 and ACT 2, actuator, vent valves 4QH1 and 4QH2 see/feel indicators show closed:
1 Disconnect ACT 1 presurized air supply hose connection.
2 Install blank to ACT 1 air supply point as in AMM 28-28-00-720-001.
(b) Do the test given in Para. 3.G. AMM 28-28-00-710-004 again to pressure test ACT 2 only.
(c) If the gage at the test point T2 does not show a pressure (newly configured/second time):
(d) If necessary, reverse the air supply blank connections as follows:
1 Install blank to ACT 2 air supply connection AMM 28-28-00-720-001.
2 Connect ACT 1 air supply.
3 Do the Operational Test of the ACT Transfer System AMM 28-28-00-710-004 again to pressure test the ACT 1.
(e) If the gage at the test point T2 does not show a pressure (newly configured/third time):
(1) Get access AMM 28-28-55-000-001 to the:
- ACT 1 actuator, vent valve 4QH1 see/feel indicator
- ACT 2 actuator, vent valve 4QH2 see/feel indicator.
(a) The P/BSW-FUEL/ACT/AUTO (24QH) is released out.
(b) The aircraft stays in the simulated flight mode AMM 32-69-00-860-001.
(c) 10 minutes have lapsed.
(d) The simulated flight mode has not timed out.
(3) Do a check of the:
- ACT 1 actuator, vent valve 4QH1 see/feel indicator to see if it is open or closed
- ACT 2 actuator, vent valve 4QH2 see/feel indicator to see if it is open or closed.
- closed, go to step (10).
- open, go to step (7).
(6) If only the ACT 2 actuator, vent valve 4QH2 is open, do step (9).
(7) If the ACT 1 and ACT 2, actuator, vent valves 4QH1 and 4QH2 see/feel indicators show open:
(a) Make sure that the Actuator Air Shut-off Valve connector 3QH-A is correctly connected to the 3QH receptacle.
NOTE: This step is necessary because the vent valves shut 28VDC supply comes from the air shut-off valve actuator when powered to open.
(b) If the fault continues: 1 Do a check of and replace, if necessary, the ACTUATOR-AIR SHUTOFF VALVE, ACT [3QH] AMM 28-28-56-000-001 and AMM 28-28-56-400-001.
NOTE: This step is necessary because even if the actuator has taken up the correct position, the open microswitch and/or the internal wiring may have a fault.
2 Do a check of the aircraft wiring ASM 282804 between the: - actuator air shutoff valve connector 3QH-A, pin C and the ACT 1, aircraft to tank connector 7619VC1, pin 19
- actuator air shutoff valve connector 3QH-A, pin C and the ACT 2, aircraft to tank connector 7619VC2, pin 19.
NOTE: The aircraft wiring, 28VDC close/shut supply, is common to the two actuator, vent valves from the actuator air shutoff valve connector 3QH-A, pin C to the terminal block 7505VT, terminal E AWM 282804.
a Repair all the unserviceable wiring and connectors ESPM 2053210. b Do the Operational Test of the ACT Automatic Transfer System AMM 28-28-00-710-004.
(8) If only the ACT 1 actuator, vent valve 4QH1 see/feel indicator shows open:
(a) Disconnect the ACTUATOR VENT VALVE, ACT 1 (4QH1) connector 4QH1-A.
(b) Do a test, with a multimeter, at the connector 4QH1-A, between the pins B (+ve) and E (-ve) ASM 282804 to see if 28VDC is available.
1 If the voltage is correct do a check of and replace, if necessary:
a The ACTUATOR-VENT VALVE, ACT1 [4QH1] AMM 28-28-55-000-001 and AMM 28-28-55-400-001.
b The
2 If the voltage is not correct do a check of the aircraft wiring AWM 282804 between:
- the actuator air shutoff valve connector 3QH-A, pin C and the ACT 1 to aircraft tank break connector 7619VC1, pin 19
- the ACT 1 to aircraft tank break connector 7619VC1-A, pin 19 and the actuator-vent valve, connector 4QH1-A, pin B
- the ACT 1 to aircraft tank break connector 7619VC1, pin 8 and the ground point DC1
- the ACT 1 to aircraft tank break connector 7619VC1-A, pin 8 and the actuator-vent valve, connector 4QH1-A, pin E.
b Do the Operational Test of the ACT Automatic Transfer System AMM 28-28-00-710-004.
c If the fault continues (no pressure at pressure gage T2, when the actuator air shut-off and vent valves are in the correct positions) do step (10).
(9) If only the ACT 2 actuator, vent valve 4QH2 see/feel indicator shows open:
(a) Disconnect the ACTUATOR VENT VALVE, ACT 2 (4QH2) connector 4QH2-A.
(b) Do a test, with a multimeter, at the connector 4QH2-A, between the pins B (+ve) and E (-ve) ASM 282804 to see if 28VDC is available.
1 If the voltage is correct do a check of and replace, if necessary:
a The ACTUATOR-VENT VALVE, ACT2 [4QH2] AMM 28-28-55-000-001 and AMM 28-28-55-400-001.
b The VALVE-VENT, ACT2 [167QM2] AMM 28-28-35-000-001 and AMM 28-28-35-400-001.
2 If the voltage is not correct do a check of the aircraft wiring AWM 282804 between:
- the actuator air shutoff valve connector 3QH-A, pin C and the ACT 2 to aircraft tank break connector 7619VC2, pin 19
- the ACT 2 to aircraft tank break connector 7619VC2-A, pin 19 and the actuator-vent valve, connector 4QH2-A, pin B
- the ACT 2 to aircraft tank break connector 7619VC2, pin 8 and the ground point DC1
- the ACT 2 to aircraft tank break connector 7619VC2-A pin 8 and the actuator-vent valve, connector 4QH2-A, pin E.
b Do the Operational Test of the ACT Transfer System AMM 28-28-00-710-004.
c If the fault continues (no pressure at pressure gage T2, when the actuator air shut-off and vent valves are in the correct position) do step (10).
(10) If the ACT 1 and ACT 2, actuator, vent valves 4QH1 and 4QH2 see/feel indicators show closed:
NOTE: All the actuators that follow are in the correct positions (for an ACT automatic fuel transfer) but the pressure gage at the test point T2 fails to pressurize.
Actuator Air Shut-off Valve (3QH) - open
Actuator Vent Valve, ACT 1 (4QH1) - closed
Actuator Vent Valve, ACT 2 (4QH2) - closed
(a) Stop the auto transfer test. Actuator Air Shut-off Valve (3QH) - open
Actuator Vent Valve, ACT 1 (4QH1) - closed
Actuator Vent Valve, ACT 2 (4QH2) - closed
1 Disconnect ACT 1 presurized air supply hose connection.
2 Install blank to ACT 1 air supply point as in AMM 28-28-00-720-001.
(b) Do the test given in Para. 3.G. AMM 28-28-00-710-004 again to pressure test ACT 2 only.
(c) If the gage at the test point T2 does not show a pressure (newly configured/second time):
- replace the ACT 2 AMM 28-11-27-000-001 and AMM 28-11-27-400-001
or - troubleshoot the ACT 2 off the aircraft.
NOTE: It is important that an ACT is pressure tested before it is installed in the aircraft.
1 Do the Operational Test of the ACT Transfer System AMM 28-28-00-710-004 again. (d) If necessary, reverse the air supply blank connections as follows:
1 Install blank to ACT 2 air supply connection AMM 28-28-00-720-001.
2 Connect ACT 1 air supply.
3 Do the Operational Test of the ACT Transfer System AMM 28-28-00-710-004 again to pressure test the ACT 1.
(e) If the gage at the test point T2 does not show a pressure (newly configured/third time):
- replace the ACT 1 AMM 28-11-27-000-001 and AMM 28-11-27-400-001
or - troubleshoot the ACT 1 because of air pressure leakage.
NOTE: It is important that an ACT is pressure tested before it is installed in the aircraft.