APU No Load Operation (131-9(A))

TASK 49-00-00-860-809-A
APU No Load Operation (131-9(A))

WARNING: MAKE SURE THAT THE FWD AVIONICS ACCESS DOOR 811 IS OPEN WITH A WARNING PLACARD ATTACHED TO IT. THE WARNING NOTICE MUST TELL PERSONS NOT TO CLOSE THE DOOR. THIS PREVENTS ACCIDENTAL PRESSURIZATION OF THE AIRCRAFT.

WARNING: DO NOT TOUCH THE APU UNTIL IT IS SUFFICIENTLY COOL TO PREVENT BURNS WHEN YOU DO THE MAINTENANCE TASK(S).

WARNING: WHILE THE APU OPERATES, DO NOT GO INTO THESE AREAS:

THE AREA BEHIND THE APU EXHAUST DUCT: 25m (82ft.) REARWARD OF THE DUCT, MORE THAN 3m (10ft.) ABOVE THE GROUND, AND THE WIDTH OF THE HORIZONTAL STABILIZER
THE AREA AROUND THE APU AIR-INTAKE: 2m (7ft) AROUND THE INTAKE
THE AREA OF THE OIL-COOLER OUTLET.

THERE IS A RISK OF INJURY IF YOU GO INTO THESE AREAS.

CAUTION: DO NOT START OR TRY TO START THE APU MORE THAN THREE TIMES, ONE AFTER THE OTHER. AFTER THE THIRD TIME, THERE MUST BE A MINIMUM OF ONE HOUR BEFORE YOU START OR TRY TO START THE APU AGAIN. THIS MAKES SURE THAT THE TEMPERATURE OF THE STARTER MOTOR DECREASES SUFFICIENTLY.

CAUTION: DO NOT TRY TO START THE APU AGAIN DURING A REFUEL/DEFUEL PROCEDURE AFTER AN AUTOMATIC SHUTDOWN OR FAILED APU START. IF YOU DO, THERE IS A RISK OF INJURY AND/OR DAMAGE.

CAUTION: OBEY THE SAFETY PRECAUTIONS.

CAUTION: DO NOT USE THE APU DURING FLUID DE-ICING OPERATIONS. DE-ICING FLUID CAN CONTAMINATE THE INSIDE OF THE APU.

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
811

C. Referenced Information

REFERENCE	DESIGNATION
TASK 23-44-00-860-001-A	Operation of the Service Interphone System
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 24-42-00-862-001-A	De-energize the Ground Service Network Supplied from the External Power
TASK 26-22-00-710-001-A	Operational Test of the APU Fire-Extinguishing Loop/Squib
TASK 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 31-32-00-860-001-A	Procedure to Get Access to the SYSTEM REPORT/TEST Menu Page
TASK 31-60-00-860-001-A	EIS Start Procedure
TASK 49-00-00-710-009-A	Self-Test of the ECB
TASK 52-41-00-010-002-A	Open the Avionics Compartment Doors for Access
TASK 52-41-00-410-001-A	Close the APU Doors after Access
TASK 52-41-00-410-002-A	Close the Avionics Compartment Doors after Access

3. Job Set-up
Subtask 49-00-00-941-087-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) Make sure that the danger areas are clear of persons and/or equipment.
(2) Make sure that APU access doors 315AL and 316AR are closed (Ref. AMM TASK 52-41-00-410-001).
(3) If an emergency or a malfunction occurs during operation of the APU, do the emergency shutdown procedure immediately. You can start the emergency shutdown from:

The APU FIRE PUSH pushbutton switch on the panel 20VU.
The APU SHUT OFF pushbutton switch on the panel 108VU.

NOTE: Do the emergency shutdown immediately if fire, smoke, unusual noise, fuel or oil leakage occurs.

Subtask 49-00-00-860-182-A ** ON A/C NOT FOR ALL

B. Aircraft Maintenance Configuration
(1) Open the access door 811 (Ref. AMM TASK 52-41-00-010-002).
(2) Put the WARNING NOTICE(S) in position on the opened access door 811 which tells persons not to close the door.
(3) Energize the ground service network
(Ref. AMM TASK 24-42-00-861-001).
(a) On the ELEC section on the panel 35VU:

Make sure that the BAT 1 and BAT 2 pushbutton switches are in the auto position (the ON and FAULT legends are OFF).

(4) Make sure that there is sufficient fuel in the A/C fuel system.
(5) Depressurize the aircraft hydraulic systems
(Ref. AMM TASK 29-00-00-864-001).
(6) Make a service interphone connection from the cockpit to the APU compartment area (Ref. AMM TASK 23-44-00-860-001).
(7) On the AIR COND section of the panel 30VU:

Make sure that the APU BLEED pushbutton switch is in the OFF position (the ON and FAULT legends are off).
Make sure that the X BLEED selector switch is in the AUTO position.

(8) On panel 115VU:

Make sure that both ENG MASTER control switches are in the OFF position.

(9) Do the EIS start procedure (upper ECAM DU and lower ECAM DU only)
(Ref. AMM TASK 31-60-00-860-001).
(a) On the ECAM control panel, push the APU pushbutton switch (on the lower ECAM DU, the APU page comes on).
(10) Make sure that the APU fire and overheat detection system and the APU fire extinguishing system are operational (Ref. AMM TASK 26-22-00-710-001).
(11) Remove the APU air intake and exhaust blanking plugs.
(12) If not required during operation of the APU, remove the ground support equipment, the special and standard tools and all other items.
(13) Do the ECB self test (Ref. AMM TASK 49-00-00-710-009).
(14) Get access to the APU menu page in SYSTEM REPORT/TEST (Ref. AMM TASK 31-32-00-860-001).
(a) Push the line key adjacent to the GND SCANNING indication.

Keep the GND SCANNING active during the APU no load operation.

Subtask 49-00-00-865-183-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	APU/FUEL/BLOW OFF/PUMP	2QC	B14
** ON A/C NOT FOR ALL
121VU	APU/FUEL/BLOW OFF/CTL	1QC	K39
** ON A/C NOT FOR ALL
121VU	APU/FIRE AND OVHT/DET/LOOP B	2WG	L44
121VU	APU/FIRE AND OVHT/DET/LOOP A	1WG	L43
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41
121VU	APU/FIRE/EXTIG/SQUIB/B	2WF	L39
121VU	APU/FIRE/EXTIG/SQUIB/A	1WF	L38
121VU	APU/FIRE/LP VALVE/NORM	4WF	M42
121VU	APU/FIRE/LP VALVE/STBY	3WF	M41
121VU	APU/FUEL/LP VALVE/CTL	1QF	M40
121VU	APU/FUEL/LP VALVE/SPLY	2QF	M39
121VU	APU/FUEL/PUMP/CTL	3QC	M38
** ON A/C NOT FOR ALL
121VU	APU/FUEL/BLOW OFF/CTL	1QC	P38

4. Procedure
Subtask 49-00-00-860-183-A ** ON A/C NOT FOR ALL

A. APU No Load Operation

ACTION	RESULT
1.On panel 35VU: Push the BAT1 and BAT2 pushbutton switches to the AUTO position.	On panel 35 VU: DC V battery indicators show each battery voltage (28V maximum, 21V minimum). NOTE: If the battery voltage is less than 25.5V, a battery charging-cycle of approximately 20 minutes is required.
2.On panel 11VU: Push the APU pushbutton switch on the ECAM panel.	On ECAM panel display: APU systems page comes on.
3.On panel 25VU: Push the APU MASTER SW pushbutton switch to the ON position.	On panel 25VU: The ON legend in the APU MASTER SW comes on. NOTE: The MASTER SW FAULT legend could come on if the Battery Charge Limiter does a power-up test after A/C power loss. Wait 45 seconds, recycle the APU MASTER SW then continue with the start sequence.
4.On panel 25VU: Push the APU START pushbutton switch to the ON position.	On panel 25VU: The ON legend in the APU START pushbutton switch comes on.
5.On the lower ECAM display: Do a check at 7% N.	On the lower ECAM display: N% indication increases. EGT increases.
Monitor the acceleration.	Continuous increase of EGT and N indications.
Do a check at 100% N.	On panel 25VU: The ON legend in the START pushbutton switch is off. The AVAIL legend in the START pushbutton switch is on.
6.Operate the APU at Ready to Load (RTL) condition.	On the lower ECAM display: The AVAIL indication is on. EGT in limits. N indication shows 100% N. APU generator voltage and frequency indications are displayed and in limits (no amber or red indications). The APU bleed valve indication is in closed position.
7.On panel 25VU: Release the APU MASTER SW pushbutton switch to the OFF position.	On panel 25VU: The ON legend in the APU MASTER SW pushbutton switch goes off. The AVAIL legend in the APU START pushbutton switch stays on during the APU cooldown delay of approximately 1 minute. It goes off after the APU cooldown delay is completed.
	On the lower ECAM display: The AVAIL indication goes off, when the AVAIL legend in the APU START pushbutton switch goes off. The EGT and N indications go off, when the ECB is powered down. NOTE: You must wait 2 minutes after the AVAIL legend goes off before you select BAT 1 and BAT 2 to the OFF position. This gives sufficient time for the air intake to fully close.

(1) On the GND SCANNING menu page make sure that no faults have occurred during the APU no load operation.

Subtask 49-00-00-860-183-B ** ON A/C NOT FOR ALL

A. APU No Load Operation

ACTION	RESULT
1.On panel 35VU: Push the BAT1 and BAT2 pushbutton switches to the AUTO position.	On panel 35 VU: DC V battery indicators show each battery voltage (28V maximum, 21V minimum). NOTE: If the battery voltage is less than 25.5V, a battery charging-cycle of approximately 20 minutes is required.
2.On panel 11VU: Push the APU pushbutton switch on the ECAM panel.	On ECAM panel display: APU systems page comes on.
3.On panel 25VU: Push the APU MASTER SW pushbutton switch to the ON position.	On panel 25VU: The ON legend in the APU MASTER SW comes on. NOTE: The MASTER SW FAULT legend could come on if the Battery Charge Limiter does a power-up test after A/C power loss. Wait 45 seconds, recycle the APU MASTER SW then continue with the start sequence.
4.On panel 25VU: Push the APU START pushbutton switch to the ON position.	On panel 25VU: The ON legend in the APU START pushbutton switch comes on.
5.On the lower ECAM display: Do a check at 7% N.	On the lower ECAM display: N% indication increases. EGT increases.
Monitor the acceleration.	Continuous increase of EGT and N indications.
Do a check at 100% N.	On panel 25VU: The ON legend in the START pushbutton switch is off. The AVAIL legend in the START pushbutton switch is on.
6.Operate the APU at Ready to Load (RTL) condition.	On the lower ECAM display: The AVAIL indication is on. EGT in limits. N indication shows 100% N. APU generator voltage and frequency indications are displayed and in limits (no amber or red indications). The APU bleed valve indication is in closed position.
7.On panel 25VU: Release the APU MASTER SW pushbutton switch to the OFF position.	On panel 25VU: The ON legend in the APU MASTER SW pushbutton switch goes off. The AVAIL legend in the APU START pushbutton switch goes off when speed (N) decrease below 95%.
	On the lower ECAM display: The AVAIL indication goes off, when the AVAIL legend in the APU START pushbutton switch goes off. The EGT and N indications go off, when the ECB is powered down. NOTE: You must wait 2 minutes after the AVAIL legend goes off before you select BAT 1 and BAT 2 to the OFF position. This gives sufficient time for the air intake to fully close.

(1) On the GND SCANNING menu page make sure that no faults have occurred during the APU no load operation.

5. Close-up
Subtask 49-00-00-860-184-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) On the MCDU 1(2):

Push the line key adjacent to the RETURN indication until the MCDU MENU page comes on.
Set the BRT knob to off.

(2) Make sure that the hydraulic system has returned back to the previous configuration (Ref. AMM TASK 29-00-00-864-001).
(3) De-energize the ground service network
(Ref. AMM TASK 24-42-00-862-001).
(4) Make sure that the work area is clean and clear of tools and other items.
(5) Remove the WARNING NOTICE(S).
(6) Close the access door 811 (Ref. AMM TASK 52-41-00-410-002).
(7) Put the aircraft back to its initial configuration.

[Rev.10 from 2021] 2026.04.01 12:42:47 UTC