Replacement of the APU Electrical Harness

TASK 49-15-11-960-802-A
Replacement of the APU Electrical Harness

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

WARNING: DISCONNECT THE LOW-TENSION ELECTRICAL SUPPLY 6 MINUTES BEFORE YOU START WORK ON THE IGNITION SYSTEM. THE HIGH CURRENT AND VOLTAGE WHICH ARE USED IN THE IGNITION SYSTEM CAN KILL YOU.

WARNING: DO NOT TOUCH THE IGNITION COMPONENTS BEFORE YOU COMPLETE ALL THE STEPS. THESE STEPS WILL RELEASE THE HIGH VOLTAGE FROM THE IGNITION EXCITER. IF YOU DO NOT OBEY THIS INSTRUCTION, INJURY TO PERSONS CAN OCCUR.

WARNING: LOCK THE MECHANISM OF THE ACCESS DOOR 316AR WITH THE PIP PIN WHEN YOU OPEN THE ACCESS DOOR. THIS WILL PREVENT INJURY.

WARNING: MAKE SURE THAT THE SAFETY DEVICES AND THE WARNING NOTICES ARE IN POSITION BEFORE YOU START A TASK ON OR NEAR:

THE FLIGHT CONTROLS
THE FLIGHT CONTROL SURFACES
THE LANDING GEAR AND RELATED DOORS
COMPONENTS THAT MOVE.

MOVEMENT OF COMPONENTS CAN KILL OR CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.

WARNING: BEFORE YOU START WORK, YOU MUST PUT ON A SAFETY HARNESS AND ATTACH IT TO THE ACCESS PLATFORM. WITHOUT A SAFETY HARNESS, YOU CAN FALL. THIS CAN KILL YOU OR CAUSE YOU INJURY.

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

CAUTION: USE THE CORRECT ASSEMBLY PROCEDURE AND TOOLS FOR THE HARNESS CONNECTOR INSTALLATION. IF YOU DO NOT, A DAMAGED OR LOOSE CONNECTOR CAN OCCUR. A LOOSE CONNECTOR CAN CAUSE UNSATISFACTORY ENGINE OPERATION, DECREASED LIGHTNING PROTECTION, AND A POSSIBLE IN-FLIGHT SHUTDOWN.

CAUTION: MAKE SURE THAT THERE IS A SUFFICIENT DISTANCE BETWEEN THE ELECTRICAL HARNESSES AND THE STRUCTURE. IF THE DISTANCE IS NOT SUFFICIENT, THERE IS A RISK OF CHAFING OF ELECTRICAL HARNESSES WITH THE STRUCTURE. CHAFING CAUSED BY OPERATIONAL VIBRATIONS CAN CAUSE MUCH DAMAGE ON ELECTRICAL HARNESSES AND WIRING.

CAUTION: DO NOT TWIST OR BEND THE ELECTRICAL HARNESS WHEN YOU DISCONNECT/CONNECT THE ELECTRICAL CONNECTOR. IF YOU DO, YOU CAN CAUSE DAMAGE TO THE HARNESS AND THUS CAUSE ELECTRICAL CIRCUIT DEFECTS.

ZONE: 315
ZONE: 316

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

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE
No specific	AR	CAP - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 56 and 51 lbf.in (0.63 and 0.58 m.daN )

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.03ABA1)	Synthetic base Lubricating Oil-Turbine Engine - -
(Material No.03ABB1)	Synthetic base Lubricating Oil-Turbine Engine Low Temp. -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
315	TAIL CONE APU AND ACCESSORY COMPARTMENT
316	TAIL CONE APU AND ACCESSORY COMPARTMENT
315AL, 316AR

D. Referenced Information

REFERENCE	DESIGNATION
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 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 49-00-00-710-005-A	Self-Test of the ECB
TASK 49-00-00-710-008-A	Operational Test of the APU
TASK 52-41-00-010-001-A	Open the APU Doors for Access
TASK 52-41-00-410-001-A	Close the APU Doors after Access
APU Electrical Harness
APU Electrical Harness
APU Electrical Harness
APU Electrical Harness
APU Electrical Harness
APU Electrical Harness
APU Electrical Harness
APU Electrical Harness
APU Electrical Harness

3. Job Set-up
Subtask 49-15-11-860-052-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Energize the ground service network
(Ref. AMM TASK 24-42-00-861-001).
(2) On panel 25VU, make sure that the APU MASTER pushbutton switch is in the OFF position.
(3) Put a WARNING NOTICE(S) in position in the cockpit to tell persons not to start the APU.
(4) Make sure that the hydraulic systems are depressurized
(Ref. AMM TASK 29-00-00-864-001).

Subtask 49-15-11-865-052-A ** ON A/C NOT FOR ALL

B. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41

Subtask 49-15-11-010-051-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put an ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE below APU access doors 315AL and 316AR.
(2) Open APU access doors 315AL and 316AR (Ref. AMM TASK 52-41-00-010-001).
(3) Set LIGHT control switch 11LJ to ON.

4. Procedure
Subtask 49-15-11-020-055-A ** ON A/C NOT FOR ALL

A. Removal of the APU Electrical Harness

CAUTION: PUT BLANKING CAPS ON THE OPEN ELECTRICAL CONNECTORS AFTER YOU DISCONNECTED THEM. IF YOU DO NOT DO THIS, CONTAMINATION OF THE CONNECTORS CAN OCCUR.

(1) Put and hold the new APU electrical harness (harness) in position before you remove the installed harness (1).
(2) Record the wire routing and the position of each clamp, spacer, washer, bolt and nut for the installation procedure.
(3) Before you disconnect the electrical connectors, make sure that there is an identification on them. This is important for the subsequent installation procedure.
(4) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
(a) To prevent contamination, put blanking caps on all the disconnected electrical connectors each time you disconnect a connector.
(5) Disconnect connector P5 from the oil differential-pressure switch.
(6) Disconnect connector P14 from the oil pressure switch.
(7) Disconnect connector P8 from the oil level sensor.
(8) Disconnect connector P24 from the discharge pressure sensor of the load compressor.
(9) Disconnect connector P29 from the discharge temperature sensor of the load compressor.
(10) Disconnect connector P22 from the inlet pressure/temperature sensor.
(11) Remove the bolts (31) and (33) and the clamps (30) and (32).
(12) Disconnect connector P33 from the bleed control valve.
(13) Disconnect connector P21 from the Inlet Guide Vane (IGV) actuator.
(14) Disconnect connector P30 from thermocouple TC1.
(15) Disconnect connector P31 from thermocouple TC2.
(16) Remove the bolts (11) and the clamps (10).
(17) Disconnect connector P10 from the ignition unit.
(18) Disconnect connectors P26 and P27 from speed sensors 1 and 2.
(19) Remove the bolt (25), clamp (24) and nut (29).
(20) Remove the bolt (27), clamp (26) and spacer (28).
(a) Hold the spacer (28) in position when you remove the bolt (27).
(21) Disconnect connector P28 from the cooling fan.
(22) Disconnect connector P20 from the identification module.
(23) Disconnect connector P15 from the de-oiling solenoid valve.
(24) Disconnect connector P25 from the oil-sump temperature sensor.
(25) Disconnect connector P32 from the starter control.
(26) Disconnect connector P19 from the Fuel Control Unit (FCU).
(27) Disconnect connector P17 from the low fuel-pressure switch.
(28) Disconnect connector P4 from the generator.
(29) Disconnect connector P6 from the oil differential-pressure switch.
(30) Disconnect connectors P1, P2 and P3.
(31) Remove the bolts (22), washers (23), spacers (12) and clamps (9).
(a) Hold the spacers (12) in position when you remove the bolts (22).
(32) Remove the screw (34), washer (35), spacer (36) and clamp (37).
(33) Remove the bolts (4), washers (3) and clamps (2).
(34) Remove the bolts (5), nuts (8) and clamps (6) and (7).
(35) Remove the harness (1) from the APU.

Subtask 49-15-11-420-056-A ** ON A/C NOT FOR ALL

B. Installation of the APU Electrical Harness
(1) Put the new harness (1) in position.
(2) Remove the CAP-BLANKING from each electrical connector and receptacle.
(3) Make sure that all the electrical connections are clean and in the correct condition.
(4) Connect connector P5 to the oil differential-pressure switch.
(5) Connect connector P6 to the oil differential-pressure switch.
(6) Connect connector P14 to the oil pressure switch.
(7) Connect connector P8 to the oil lever sensor.
(8) Connect connector P24 to the discharge pressure sensor of the load compressor.
(9) Connect connector P29 to the discharge temperature sensor of the load compressor.
(10) Connect connectors P26 and P27 to speed sensors 1 and 2.
(11) Connect connector P22 to the inlet/pressure temperature sensor.
(12) Connect connector P33 to the bleed control valve.
(13) Connect connector P21 to the IGV actuator.
(14) Connect connector P30 to thermocouple TC1.
(15) Connect connector P31 to thermocouple TC2.
(16) Connect connector P10 to the ignition unit.
(17) Connect connector P28 to the cooling fan.
(18) Connect connector P20 to the identification module.
(19) Connect connector P15 to the de-oiling solenoid valve.
(20) Connect connector P25 to the oil-sump temperature sensor.
(21) Connect connector P32 to the starter motor.
(22) Connect connector P4 to the generator.
(23) Connect connector P19 to the FCU.
(24) Connect connector P17 to the low fuel-pressure switch.
(25) Connect connectors P1, P2 and P3.
(26) Lubricate the threads of the bolts (4), (5), (11), (22), (25), (27), (31) and (33) with Synthetic base Lubricating Oil-Turbine Engine - - (Material No.03ABA1) or Synthetic base Lubricating Oil-Turbine Engine Low Temp. - (Material No.03ABB1) .
(27) Attach the harness (1) with the clamps (10).
(28) Put the clamps (10) in position and install the bolts (11).
(29) TORQUE the bolts (11) to between 56 and 51 lbf.in (0.63 and 0.58 m.daN )

.
(30) Attach the harness (1) with the clamps (9).
(31) Put the clamps (9) in position and install the spacers (12), washers (23) and bolts (22).
(32) TORQUE the bolts (22) to between 56 and 51 lbf.in (0.63 and 0.58 m.daN )

.
(33) Attach the harness (1) with the clamps (6) and (7).
(34) Put the clamps (7) in position on the clamps (6).
(35) Install the bolts (5) and the nuts (8).
(36) TORQUE the nuts (8) to between 56 and 51 lbf.in (0.63 and 0.58 m.daN )

.
(37) Attach the harness (1) with the clamps (2).
(38) Install the bolts (4) and the washers (3).
(39) Tighten the bolts (4).
(40) Attach the harness (1) with the clamps (30) and (32).
(41) Install the bolts (31) and (33).
(42) TORQUE the bolts (31) and (33) to between 56 and 51 lbf.in (0.63 and 0.58 m.daN )

.
(43) Attach the harness (1) with the clamps (24) and (26).
(44) Put the clamp (24) in position.
(45) Install the bolt (25) and the nut (29).
(46) TORQUE the nut (29) to between 56 and 51 lbf.in (0.63 and 0.58 m.daN )

.
(47) Put the clamp (37) in position.
(48) Attach the harness (1) with the clamp (37).
(49) Install the screw (34), washer (35) and spacer (36).
(50) Tighten the screw (34).
(50) Put the clamp (26) in position.
(51) Install the bolt (27) and the spacer (28).
(52) TORQUE the bolt (27) to between 56 and 51 lbf.in (0.63 and 0.58 m.daN )

Subtask 49-15-11-865-053-A ** ON A/C NOT FOR ALL

C. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41

Subtask 49-15-11-710-051-A ** ON A/C NOT FOR ALL

D. Test
(1) Do the ECB self-test (Ref. AMM TASK 49-00-00-710-005).
(2) Do the operational test of the APU (Ref. AMM TASK 49-00-00-710-008).

5. Close-up
Subtask 49-15-11-410-051-A ** 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) Set the LIGHT control switch 11LJ to OFF.
(3) Close APU access doors 315AL and 316AR (Ref. AMM TASK 52-41-00-410-001).
(4) Remove the access platform(s).

Subtask 49-15-11-860-053-A ** ON A/C NOT FOR ALL

B. Aircraft Maintenance Configuration
(1) De-energize the ground service network
(Ref. AMM TASK 24-42-00-862-001).
(2) Put the aircraft back to its initial configuration.
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 01:27:28 UTC