Fuel Pumps - ACT Manual Transfer Pump 1QH System Malfunction

TASK 28-28-00-810-801-A
Fuel Pumps - ACT Manual Transfer Pump 1QH System Malfunction

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

WARNING: DO NOT CLOSE AN OPEN (TRIPPED) CIRCUIT BREAKER RELATED TO A FUEL-PUMP. IF YOU CLOSE THE CIRCUIT BREAKER, THERE IS A RISK:

OF FIRE OR OF AN EXPLOSION
OF DAMAGE TO THE AIRCRAFT WIRING AND STRUCTURE.

1. Possible Causes

PUMP-FUEL TRANSFER, ACT [1QH]
MOUNTING PLATE-FUEL TRANSFER PUMP, ACT [163QM]
VALVE-REFUEL, ACT [41QU]
CHECK VALVE-ACT TRANSFER [176QM]
VALVE-THERMAL RELIEF, ACT TRANSFER [169QM]
C/B-ACT PUMP SUPPLY [25QH]
CONTACTOR-ACT PUMP SUPPLY [26QH]
aircraft wiring
SWITCH-INDICATOR, ACT [24QH]
C/B-ACT XFR VALVE MAN CTL [30QH]
PRESSURE SWITCH-FUEL TRANSFER PUMP, ACT [2QH]
safety valve
plug (banjo adaptor attachment bolt)
pressure switch fuel supply pipe-line between the ACT transfer pump mounting plate (163QM) and the pressure switch (2QH)
RELAY-LOW LEVEL OVERRIDE, ACT [17QH]
RELAY-LOW PRESSURE DELAY [27QH]

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

REFERENCE	QTY	DESIGNATION
No specific	AR	MULTIMETER - STANDARD
No specific	AR	TESTER - INSULATION, 500 V

B. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 28-13-00-810-801-A	Fuel - Leak Shows at Drain Mast
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 28-28-00-810-807-A	Fuel - ACT 2 Sequence Failure
TSM TASK 28-28-00-810-807-A-01	Fuel - ACT 2 Sequence Failure (802VU ACT Relay Testbox)
TSM TASK 28-28-00-810-824-A	Fuel Pumps - ACT Manual Transfer Pump, Power Supply - C/B-25QH Tripped
AMM 25-71-11-000-001	Removal of the Additional Center-Tank (ACT) Relay-Box 802VU
AMM 25-71-11-400-001	Installation of the Additional Center-Tank (ACT) Relay-Box 802VU
AMM 28-11-49-000-001	Removal of the ACT Integrated Impact Wall
AMM 28-11-49-400-001	Installation of the ACT Integrated Impact Wall
AMM 28-25-51-000-004	Removal of the Refuel Valve
AMM 28-25-51-400-004	Installation of the Refuel Valve
AMM 28-28-00-710-001	Operational Check of the ACT Manual Transfer System
AWM 282802
AMM 28-28-11-000-001	Removal of the ACT Fuel Transfer-Pump Pressure-Switch
AMM 28-28-11-400-001	Installation of the ACT Fuel Transfer-Pump Pressure-Switch
AMM 28-28-31-000-001	Removal of the ACT Fuel-Transfer-Pump Mounting-Plate
AMM 28-28-31-400-001	Installation of the ACT Fuel-Transfer-Pump Mounting-Plate
AMM 28-28-51-000-001	Removal of the ACT Fuel-Transfer Pump-Element
AMM 28-28-51-400-001	Installation of the ACT Fuel-Transfer Pump-Element
AMM 57-17-11-000-003	Removal of the Protective Cover of the ACT-Equipment Support Door
AMM 57-17-11-400-003	Installation of the Protective Cover of the ACT-Equipment Support Door

3. Fault Confirmation
Subtask 28-28-00-865-066-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	ACT XFR VALVE MAN CTL	30QH	N29
121VU	ACT PUMP SUPPLY	25QH	Q29

Subtask 28-28-00-710-050-A ** ON A/C NOT FOR ALL

B. Test

WARNING: DO NOT CLOSE AN OPEN (TRIPPED) CIRCUIT BREAKER RELATED TO A FUEL-PUMP. IF YOU CLOSE THE CIRCUIT BREAKER, THERE IS A RISK:

OF FIRE OR OF AN EXPLOSION
OF DAMAGE TO THE AIRCRAFT WIRING AND STRUCTURE.

(1) Examine the C/B-ACT PUMP SUPPLY (25QH).
(2) If the C/B-25QH:
(a) Is open (tripped), do the procedure Fuel Pumps - ACT Manual Transfer Pump, Power Supply - C/B-25QH Tripped (Ref. TSM TASK 28-28-00-810-824).
(b) Is closed (set):
1 Do a check of the three leak monitors (Ref. TSM TASK 28-13-00-810-801).
2 If you find fuel in a leak monitor, do the related trouble-shooting (Ref. TSM TASK 28-13-00-810-801).

NOTE: It is important to make sure that there are no fuel leaks in the ACT system assemblies before you do the test that follows.

3 Do the Operational Test of the ACT Manual Transfer System AMM 28-28-00-710-001.

NOTE: The PUMP-FUEL TRANSFER, ACT (1QH) operates independently of system inhibits.

NOTE: If the fuel pump motor (1QH) can be heard to operate it does not necessarily operate correctly. The impeller or inducer can be damaged.

NOTE: If the center tank is full of fuel it will inhibit/stop a manual transfer by keeping the ACT 1 inlet valve closed (when the aircraft is on the ground).
In a similar manner a failure to energize the 501PP FUELLING BUS 28VDC, will cause the center tank high level channel LS7 of the sensor (20QJ) (in the FLSCU-1 (7QJ)) to give a false WET output (not powered - de-energized condition).
It is therefore important to make sure that the REFUEL panel door 192MB/522KB/622KB is open during the operational test.
OR (if possible/installed)
The P/BSW-REFUEL PWR (23QU) is set to on.

NOTE: The P/BSW-FUEL/ACT/AUTO (24QH) FAULT legend/light can come on for up to approximately ten (10) minutes if it is necessary for the fuel pump (impeller type) to prime/reprime the system. When the fuel pressure builds up sufficiently to operate the pressure switch (by the action of the ACT fuel transfer pump), the FAULT legend will go off.
During flight or flight simulation the FAULT legend/light operation is inhibited until at least one of the ACT 1 low level sensors has been dry for four minutes (4) minutes.
The four minute delay is the sum of the relay operation as follows:

RELAY-LO LVL SENSE, ACT 1 (3QH), one (1) minute
RELAY-LO PRESSURE DELAY (27QH), three (3) minutes.

4. Fault Isolation
Subtask 28-28-00-810-050-C ** ON A/C NOT FOR ALL

A. Procedure

NOTE: This procedure is only applicable when an ACT 1 and an ACT 2 are installed and the two are configured for operation.

(1) If necessary, remove the applicable protective covers as follows:

Protective Cover of the ACT-Equipment Support Door (147BZ) AMM 57-17-11-000-003
Impact Wall/Heat Shield from the rear side of the ACT 2 AMM 28-11-49-000-001
Cabin Floor Access Panels.

(2) On the FUEL System Display:

examine the center tank, the ACT 1 and the ACT 2 fuel quantity indications (FQIs) and make a note of their amounts. This is to see which of the ACTs will be selected to transfer fuel forward.

NOTE: In normal operation ACT 2 fuel is used before ACT 1 fuel.

(3) Use a multimeter to do a test, for 28 VDC, at the relay panel (802VU) TEST connector 4068VC, pin E.
(4) If the voltage at Test connector 4068VC, pin E, shows:
(a) Zero VDC and the ACT 2, FQI is more than/or approximately 100 kg (220 lb), do step (5).

NOTE: This indicates that the RELAY-18QH is in the ACT 2 position.

(b) 28VDC and the ACT 2, FQI is more than 100 kg (220 lb), do ACT 2 Sequence Failure (Ref. TSM TASK 28-28-00-810-807).
(c) Zero VDC and the ACT 2, FQI is less than 100 kg (220 lb), do ACT 2 Sequence Failure (Ref. TSM TASK 28-28-00-810-807).
(d) 28VDC and the ACT 2, FQI is approximately/or less than 100 kg (220 lb), do step (6)

NOTE: This indicates that the RELAY-18QH is in the ACT 1 position.

(5) Examine the see/feel indicator positions of the actuators shown in the table that follows.
(a) ACT 2 Fuel Transfer - Actuator and Valve Positions:

ACTUATOR FUNCTIONAL DESIGNATION	FIN	CORRECT MANUAL XFR POSITION	SDAC ARINC LABEL
ACTUATOR-FUEL XFR VALVE	6QH	OPEN	002-00/28
ACTUATOR-FUEL INLET VALVE, ACT 1	5QH1	CLOSED	004-01/25
ACTUATOR-FUEL VENT VALVE, ACT 1	4QH1	CLOSED	NOT MONITORED
ACTUATOR-FUEL INLET VALVE, ACT 2	5QH2	OPEN	004-00/25
ACTUATOR-FUEL VENT VALVE, ACT 2	4QH2	OPEN	NOT MONITORED

NOTE: The actuator (4QH2) position is not critical during an ACT 2 manual transfer. This is because as fuel is moved (forward from the ACT) air can go into the ACT 2 through its valve inward pressure relief, ACT (2) (172QM2).

NOTE: The related ARINC labels have been included in the table to let the user monitor the system electronically (if AIDS or an ARINC reader is available).

(b) If the see/feel indicators are:
1 In the correct positions as specified, go to Step (7).
2 Not in the correct positions as specified, do the ACT 2 Sequence Failure (Ref. TSM TASK 28-28-00-810-807).
(6) The ACT 2 shows a fuel quantity of less than/or approximately 100 kg (220 lb)
Examine the see/feel indicator positions of the actuators shown in the table that follows.
(a) ACT 1 Fuel Transfer - Actuator and Valve Positions:

ACTUATOR FUNCTIONAL DESIGNATION	FIN	CORRECT MANUAL XFR POSITION	SDAC ARINC LABEL
ACTUATOR-FUEL XFR VALVE	6QH	OPEN	002-00/28
ACTUATOR-FUEL INLET VALVE, ACT 1	5QH1	OPEN	004-01/25
ACTUATOR-FUEL VENT VALVE, ACT 1	4QH1	OPEN	NOT MONITORED
ACTUATOR-FUEL INLET VALVE, ACT 2	5QH2	CLOSED	004-00/25
ACTUATOR-FUEL VENT VALVE, ACT 2	4QH2	CLOSED	NOT MONITORED

NOTE: The actuator (4QH1) position is not critical during an ACT 1 manual transfer. This is because as fuel is moved (forward from the ACT) air can go into the ACT 1 through its valve inward pressure relief, ACT 1 (172QM1).

NOTE: The related ARINC labels have been included in the table to let the user monitor the system electronically (if AIDS or an ARINC reader is available).

(b) If the see/feel indicators are:
1 In the correct positions as specified, go to Step (7).
2 Not in the correct positions as specified, do the ACT 1 Manual Transfer Failure (Ref. TSM TASK 28-28-00-810-802).
(7) Do a check, for signs of damage or incorrect installation, of:

NOTE: Air Ingress
An ACT pumped transfer can be stopped or slowed if air leaks in at these positions/connections.

(a) The refuel transfer line to the ACT 1 (fuel pipe line) connection.

NOTE: Access to the fuel line connection is through the access:

panel (241NF) in the floor of the passenger compartment
panel (151KC) in the ceiling of the aft cargo compartment.

(b) The ACT 1 to the ACT 2 refuel transfer line (fuel pipe line) connection.

NOTE: Access to the fuel line connection is through the acess:

panel (251KG) in the floor of the passenger compartment
panel (151NC) in the ceiling of the aft cargo compartment.

(c) The ACT 2 rear wall fuel pipe line blanked connection.
(d) Repair all the unserviceable pipes, blanks and connections.
(8) If fuel transfers go to step (10). If fuel does not transfer from ACT 2 or ACT 1:
(a) Set the P/BSW-FUEL/ACT/AUTO (24QH) to AUTO (release out). This will switch off the fuel pump (1QH).
(b) Disconnect the electrical supply cable end connector (1QH-A) from the pump receptacle.
(c) Set the P/BSW-FUEL/ACT/AUTO (24QH) to FWD/MAN (push in). This will close the contactor (26QH) and the 115VAC three phases will be supplied to the end connector 1QH-A.
1 Make sure that the white FWD legend/light comes on.
(d) Use a MULTIMETER - STANDARD to do a test, to make sure that each of the 115VAC 3 phases are available at the supply cable end connector 1QH-A AWM 282802.
(e) Set the P/BSW-FUEL/ACT/AUTO (24QH) to AUTO (release out). This will switch off the fuel pump (1QH) 115VAC three phase supply to the end connector 1QH-A.
(f) If the 115VAC three phase supply voltage is correct, do a check of and replace, if necessary:
1 The PUMP-FUEL TRANSFER, ACT [1QH] AMM 28-28-51-000-001 and AMM 28-28-51-400-001.
2 The fuel inlet and the fuel outlet valves, part of the MOUNTING PLATE-FUEL TRANSFER PUMP, ACT [163QM] AMM 28-28-31-000-001 and AMM 28-28-31-400-001.
3 The VALVE-REFUEL, ACT [41QU] AMM 28-25-51-000-004 and AMM 28-25-51-400-004.

NOTE: An ACT pumped transfer can be slowed if fuel or air leaks in from the refuel gallery.

4 The CHECK VALVE-ACT TRANSFER [176QM] .

NOTE: An ACT pumped transfer can be slowed if fuel or air leaks in from the center tank.

5 The VALVE-THERMAL RELIEF, ACT TRANSFER [169QM] .

NOTE: An ACT pumped transfer can be slowed if fuel or air leaks in from the center tank.

6 If the fault continues, do a check of the refuel transfer line (between the ACT 1 and the center tank) for damage, leaks or incorrect installation.
7 Repair all the unserviceable pipes and connections.
8 Do the test given in Para. 3.B.(2)(b).
(g) If the 115VAC three phase supply voltage is not correct (no voltage, incorrect voltage or a phase is not available):
1 Do a visual check, for easily seen damage, of these items:

the fuel pump receptacle
the supply cable end connector 1QH-A
the supply cable (part of the harness 5675VB) between the end connector 1QH-A and the pressure seal feed through 7509VP on the roof of the left Main Landing Gear (MLG) bay
the aircraft structure adjacent to the route of the supply cable in the left MLG bay.

NOTE: Damage to the fuel-pump supply-cable insulation can cause electrical arcing and damage the aircraft structure.

2 Repair, replace or make serviceable items found unserviceable in step 1_.
3 If the aircraft structure is damaged, refer to the Aircraft Structural Repair Manual (ASRM).
4 Do a check of AWM 282802 and replace, if necessary:
a The C/B-ACT PUMP SUPPLY [25QH] .
b The CONTACTOR-ACT PUMP SUPPLY [26QH] .
5 Use a MULTIMETER - STANDARD and a TESTER - INSULATION, 500 V do a check of the aircraft wiring (three phase electrical supply) AWM 282802 between:

the C/B-ACT PUMP SUPPLY (25QH) and the CONTACTOR-ACT PUMP SUPPLY (26QH)
the CONTACTOR-ACT PUMP SUPPLY (26QH) and the PUMP-FUEL XFR, ACT end connector 1QH-A.

6 Repair all the unserviceable wiring and connectors.
7 The fuel pump supply cable must stay disconnected.
8 Make sure that the C/B-25QH is closed.
9 Set the P/BSW-FUEL/ACT/AUTO (24QH) to FWD/MAN (push in).
10 If the C/B-25QH opens (trips), set the P/BSW-FUEL/ACT/AUTO (24QH) to AUTO (release out) and then do steps 1_ thru 9_ again.
11 If the C/B-25QH stays closed, set the P/BSW-FUEL/ACT/AUTO (24QH) to AUTO (release out).
12 Connect the supply cable end connector (1QH-A) to the fuel pump receptacle.
13 Do the test given in Para. 3.B.(2)(b).
14 If the fuel pump is serviceable, do the close-up given in Para. 5.A. and then do the test given in Para. 3.A.(2)(b) again.
15 If the C/B-25QH opens (trips), do a check of and replace, if necessary, the PUMP-FUEL TRANSFER, ACT [1QH] AMM 28-28-51-000-001 and AMM 28-28-51-400-001.
16 Do the test given in Para. 3.B.(2)(b).
17 If the fuel pump is serviceable, do the close-up given in Para. 5.A. and then do the test given in Para. 3.A.(2)(b) again.
(h) If the fault continues (28VDC fuel pump contactor control supply):
1 Do a check of AWM 282802 and replace, if necessary:

the SWITCH-INDICATOR, ACT [24QH]
the C/B-ACT XFR VALVE MAN CTL [30QH] .

2 Do a check of the aircraft wiring AWM 282802 between:

the CONTACTOR-ACT PUMP SUPPLY (26QH), terminal X and the P/BSW-FUEL/ACT/AUTO (24QH), terminal C1
the P/BSW-FUEL/ACT/AUTO (24QH), terminal C3 and the C/B-ACT XFR VALVE MAN CTL (30QH), terminal 2.

3 Repair all the unserviceable wiring and connectors.
(i) Do the test given in Para. 3.B.(2)(b).
(9) If fuel transfers:
(a) Disconnect the free connector 2QH-A from the PRESS SW-FUEL PUMP, ACT (2QH) during a fuel transfer AMM 28-28-11-000-001.
(b) If the P/BSW-FUEL/ACT/AUTO (24QH) FAULT legend goes off:

do a check of and replace, if necessary, the PRESSURE SWITCH-FUEL TRANSFER PUMP, ACT [2QH] AMM 28-28-11-000-001 and AMM 28-28-11-400-001.

NOTE: The output from the fuel pressure switch can also be checked at the RELAY-PANEL (802VU) ACT test connector 4068VC, pin S.
The fuel pressure switch output should be as follows:

normal pressure (pump running) - no ground
low pressure (pump not running) - ground.

(c) If the fault continues, do a check of:
1 The safety valve
Make sure that the four passage-ways have not become blocked or that the valve operating extension has not been damaged.
2 The plug (banjo adaptor attachment bolt)
Make sure that the conical operating face of the plug has not been damaged and when installed will contact and open the safety valve.
3 The pressure switch fuel supply pipe-line between the ACT transfer pump mounting plate (163QM) and the pressure switch (2QH)
Make sure that the fuel supply pipe-line does not leak or is blocked.
4 Repair/replace the safety valve, the plug or the fuel pipe-line as necessary.
5 Do the test given in Para. 3.B.(2)(b).
(d) If the P/BSW-FUEL/ACT/AUTO (24QH) FAULT legend stays on, do a check of the aircraft wiring AWM 282802 between:

the PRESS SW-FUEL XFR PUMP, ACT free connector 2QH-A, pin C and the RELAY-PANEL free connector 4065VC, pin Y (PRESS SW O/P)
the RELAY-PANEL (802VU) free connector 4065VC-A, pin Z and the P/BSW-FUEL/ACT/AUTO (24QH) terminal B1
the P/BSW-FUEL/ACT/AUTO (24QH) terminal B1, and the SDAC-1 (1WV1), and the SDAC-2 (1WV2) connectors AD, pins 8E
the P/BSW-FUEL/ACT/AUTO (24QH) terminal B3, and the BOARD-ANN LT TEST & INTFC (20LP) connector 2LP-A, pin 34.

NOTE: A short circuit to ground on one of these lines will cause:

a false LO PR warning to be generated within the FWC
the FAULT legend/lamp to come on incorrectly.

It is possible that a short circuit to ground on one of these lines can come from one of the LRUs as follows:

SDAC-1 (1WV1)/SDAC-2 (1WV2)
BOARD-ANN LT TEST & INTFC (2LP).

(10) Repair all the unserviceable wiring and connectors.
(11) Do the test given in Para. 3.B.(2)(b).
(12) If the fault continues, replace the RELAY-PANEL (802VU) AMM 25-71-11-000-001 and AMM 25-71-11-400-001.

If there is no relay panel available, go to step (13).

(a) Do the test given in the Para. 3.B.
(13) If the fault continues:
(a) Do a check of AWM 282802 and replace, if necessary:

the RELAY-LOW LEVEL OVERRIDE, ACT [17QH]
the RELAY-LOW PRESSURE DELAY [27QH] .

(b) Do a check of the RELAY-PANEL (802VU) wiring AWM 282802 between the connector to relay lines, as shown in the table that follows:

NOTE: The circuit connections shown in the table are abbreviated, for example:

the connector 4065VC, pin Y is shown as 4065VC-Y
the RELAY-LO LVL OVERRIDE, ACT (17QH), terminal D1 is shown as RL 17QH-D1.

-----------------------------------------------------------------------------

! CONNECTOR-PIN ! RELAY-TERMINAL TO RELAY-TERMINAL ! CONNECTOR-PIN !

!-----------------------------------------------------------------------------!

! 4065VC-Y ----------------------------------- RL 17QH-D1 (ground routing) !

! RL 17QH-D2 ---------------------------------- 4065VC-Z !

! 4065VC-Y ----------------------------------- RL 27QH-A1 (flight routing) !

! RL 17QH-A2 ---------------------------------- 4065VC-Z !

-----------------------------------------------------------------------------

1 Repair all the unserviceable wiring and connectors.
2 Do the test given in Para. 3.B.(2)(b).

5. Close-up
Subtask 28-28-00-860-050-C ** ON A/C NOT FOR ALL

A. If removed, install the applicable protective covers or access panels as follows:

the Protective Cover of the ACT-Equipment Support Door (147BZ) AMM 57-17-11-400-003
the Impact Wall/Heat Shield from the rear side of the ACT 2 AMM 28-11-49-400-001
the access panel (251KG) in the floor of the passenger compartment (ACT 1)
the access panel (TBA) in the floor of the passenger compartment (ACT 2)
the access panel (151KC) in the ceiling of the aft cargo compartment (ACT 1)
the access panel (TBA) in the ceiling of the aft cargo compartment (ACT 2).

[Rev.8 from Aug 2018] 2026.04.04 04:28:48 UTC