Operational Check of Forward ACT Vent Isolation Valve

TASK 28-28-00-710-010-A
Operational Check of Forward ACT Vent Isolation Valve

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

ZONE: 130

1. Reason for the Job
Refer to the MPD TASK: 282800-62
OPERATIONAL CHECK OF FORWARD ACT VENT ISOLATION VALVE
This MPD task is applicable only when the ACT is installed.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
130	FWD CARGO COMPT AFT BULKHEAD OF AVNCS COMPT TO FWD PRESSURE BULKHEAD OF WING CENTER BOX

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
TASK 53-22-12-000-001-A	Removal of the Cabin Floor Panels
TASK 53-22-12-400-001-A	Installation of the Cabin Floor Panels
ACT FWD Vent-Isolation-Valve Actuator - Component Location

3. Job Set-up
Subtask 28-28-00-860-104-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 a WARNING NOTICE(S) in position on:

Refuel/defuel panel 800VU
Fuel panels 28VU and 40VU
to tell persons not to operate the refuel/defuel system.

Subtask 28-28-00-010-066-B ** ON A/C NOT FOR ALL

B. Get Access
(1) In the cabin compartment, remove cabin floor-panel 231BMG (Ref. AMM TASK 53-22-12-000-001).

Subtask 28-28-00-865-081-A ** ON A/C NOT FOR ALL

C. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	AFMC SPLY	3QN	B08
121VU	FUEL/ACT XFR VLV/MOT2	66QH	J18
121VU	FUEL/ACT XFR VLV/MOT1	65QH	J17
121VU	FUEL/AFMC/SPLY	4QN	K19
121VU	FUEL/ACT/FUEL PUMP/SPLY	25QH	Q29
121VU	FUEL/RFL/ON BAT	5QN	R30

4. Procedure
Subtask 28-28-00-710-063-B ** ON A/C NOT FOR ALL

A. Operational Check

ACTION	RESULT
1.On panel 121VU, open circuit breaker 69QH "FUEL/VENT/ISOL VLV/MOT2 CTL".	In the forward cargo compartment, on ACT FWD (ACT 4.1): The indicator of the vent isolation valve actuator is in the open position.
2.In the cockpit, on ACT control panel 28VU, make sure that: The FWD ACT OVRD pushbutton switch is in the OFF position (ON light is off) No FAULT indication is shown.
3.In the cockpit, set the Auxiliary Fuel Management Computer (AFMC): On panel 121VU, open circuit breaker 4QN "FUEL/AFMC/SPLY" On panel 121VU, open circuit breaker 5QN "FUEL/RFL/ON BAT" On panel 49VU, open circuit breaker 3QN "AFMC SPLY".
4.After a minimum of 10 seconds: On panel 121VU, close circuit breaker 4QN "FUEL/AFMC/SPLY" On panel 121VU, close circuit breaker 5QN "FUEL/RFL/ON BAT" On panel 49VU, close circuit breaker 3QN "AFMC SPLY".	In the forward cargo compartment, on ACT FWD: Wait for a minimum of 3 minutes and monitor the indicator of the vent isolation valve-actuator at the same time The indicator of the vent isolation valve-actuator moves from the open position to the closed position and then goes back to the open position.
5.On panel 121VU: Close circuit breaker 69QH "FUEL/VENT/ISOL VLV/MOT2 CTL".
6.On panel 49VU: Open circuit breaker 59QH "VENT ISOL VLV MOT1".
7.Do steps 3, 4, 5 and 6 again.	In the forward cargo compartment, on the ACT FWD: Monitor the indicator of the vent isolation valve-actuator during 3 minutes The indicator of the vent isolation valve-actuator goes from the open to the closed position and then back to the open position.
8.On panel 49VU, close circuit breaker 59QH "VENT ISOL VLV MOT1".

5. Close-up
Subtask 28-28-00-410-078-B ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install cabin floor panel 231BMG (Ref. AMM TASK 53-22-12-400-001).

Subtask 28-28-00-860-105-A ** ON A/C NOT FOR ALL

B. Put the aircraft back to its initial configuration.
(1) Remove the WARNING NOTICE(S).
(2) Remove the ground support and maintenance equipment, the special and standard tools and all other items.
(3) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.02 06:17:51 UTC