DOC AIRBUS | AMM A320FReplacement of the Resistor (R1) in the APU Starter-Motor Monitoring-Circuit
TASK 49-42-51-960-001-A
Replacement of the Resistor (R1) in the APU Starter-Motor Monitoring-Circuit
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Referenced Information
3. Job Set-up
Subtask 49-42-51-860-075-A ** ON A/C NOT FOR ALL
Subtask 49-42-51-960-050-A ** ON A/C NOT FOR ALL
Subtask 49-42-51-410-066-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 01:30:29 UTC
Replacement of the Resistor (R1) in the APU Starter-Motor Monitoring-Circuit
FIN: 8KA ** ON A/C NOT FOR ALL
1. Reason for the JobSelf explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 315AL, 316AR |
| 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 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 |
| AWM 491501 | |
Resistor (R1) in the APU Starter-Motor Monitoring-CircuitSubtask 49-42-51-860-075-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 the panel 25VU, make sure that the APU MASTER SW p/bsw is OFF.
(3) Put a warning notice 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 49-42-51-865-077-A ** ON A/C NOT FOR ALL (1) Energize the ground service network
(Ref. AMM TASK 24-42-00-861-001).
(2) On the panel 25VU, make sure that the APU MASTER SW p/bsw is OFF.
(3) Put a warning notice 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).
B. Open, safety and tag this(these) circuit breaker(s):
Subtask 49-42-51-010-069-A ** ON A/C NOT FOR ALL | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 121VU | APU/APU/CTL | 2KD | L42 |
| 121VU | APU/ECB/SPLY | 1KD | L41 |
C. Get Access
(1) Put the ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE in position below the APU access doors 315AL and 316AR.
(2) Open the APU access doors 315AL and 316AR (Ref. AMM TASK 52-41-00-010-001).
(3) Set the LIGHT control SW 11LJ to the ON position.
4. Procedure(1) Put the ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE in position below the APU access doors 315AL and 316AR.
(2) Open the APU access doors 315AL and 316AR (Ref. AMM TASK 52-41-00-010-001).
(3) Set the LIGHT control SW 11LJ to the ON position.
Subtask 49-42-51-960-050-A ** ON A/C NOT FOR ALL
A. Replacement of the Resistor R1
(1) Remove the cover (1) from the terminal block of the starter motor.
(2) Remove the nut (2), the washer (3) and the signal cable (4) from the positive (+) terminal stud. Keep the power cable (5) installed.
(3) Temporarily install the washer (3) and the nut (2) on the positive (+) terminal stud.
(4) Be careful and do not damage the electrical wires when you remove and discard the different layers of shrinking sleeves (8) and (6).
(5) Cut off the leads adjacent to the splices SP8 and SP9.
(6) Installation of resistor R1 (7).
(a) Connect wire X011B20 and the lead of new resistor R1 (7) with splice SP8.
(b) Apply a piece of sleeve (8) to splice SP8 and shrink the sleeve (8) with a HOT AIR BLOWER MAX OPERATING 370 DEG C (700 DEG F).
(c) Connect wire X011C20 and the other lead of new resistor R1 (7) with splice SP9.
(d) Apply a piece of sleeve (6) to splice SP9 and shrink the sleeve (6) with a HOT AIR BLOWER MAX OPERATING 370 DEG C (700 DEG F).
(e) Install the SLEEVE - SHRINKING (9) in sequence and apply heat to each one before you put the next sleeve in position.
(7) Remove the nut (2) and the washer (3) from the positive (+) terminal stud.
(8) Install the monitoring cable (4), the washer (3) and the nut (2) on the positive (+) terminal stud.
.
(10) Install the cover (1) on the terminal block of the starter motor.
Subtask 49-42-51-710-053-A ** ON A/C NOT FOR ALL (1) Remove the cover (1) from the terminal block of the starter motor.
(2) Remove the nut (2), the washer (3) and the signal cable (4) from the positive (+) terminal stud. Keep the power cable (5) installed.
(3) Temporarily install the washer (3) and the nut (2) on the positive (+) terminal stud.
(4) Be careful and do not damage the electrical wires when you remove and discard the different layers of shrinking sleeves (8) and (6).
(5) Cut off the leads adjacent to the splices SP8 and SP9.
(6) Installation of resistor R1 (7).
(a) Connect wire X011B20 and the lead of new resistor R1 (7) with splice SP8.
(b) Apply a piece of sleeve (8) to splice SP8 and shrink the sleeve (8) with a HOT AIR BLOWER MAX OPERATING 370 DEG C (700 DEG F).
(c) Connect wire X011C20 and the other lead of new resistor R1 (7) with splice SP9.
(d) Apply a piece of sleeve (6) to splice SP9 and shrink the sleeve (6) with a HOT AIR BLOWER MAX OPERATING 370 DEG C (700 DEG F).
(e) Install the SLEEVE - SHRINKING (9) in sequence and apply heat to each one before you put the next sleeve in position.
(7) Remove the nut (2) and the washer (3) from the positive (+) terminal stud.
(8) Install the monitoring cable (4), the washer (3) and the nut (2) on the positive (+) terminal stud.
NOTE: Do not add locknut and apply torque at the same time.
(9) TORQUE the nut (2) to between 1.4 and 1.3 m.daN (123.89 and 115.04 lbf.in ) . (10) Install the cover (1) on the terminal block of the starter motor.
B. Resistance Check
(1) Do a check for a resistance of 10 KOhms of the repaired wiring with a MULTIMETER - STANDARD between ECB pin 59KD-AB/10J and STARTER MOTOR pin 8KA (+) AWM 491501.
5. Close-up(1) Do a check for a resistance of 10 KOhms of the repaired wiring with a MULTIMETER - STANDARD between ECB pin 59KD-AB/10J and STARTER MOTOR pin 8KA (+) AWM 491501.
Subtask 49-42-51-410-066-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 the OFF position.
(3) Close the APU access doors 316AR 315AL (Ref. AMM TASK 52-41-00-410-001).
(4) Remove the access platform(s).
Subtask 49-42-51-865-078-A ** ON A/C NOT FOR ALL (1) Make sure that the work area is clean and clear of tools and other items.
(2) Set the LIGHT control switch 11LJ to the OFF position.
(3) Close the APU access doors 316AR 315AL (Ref. AMM TASK 52-41-00-410-001).
(4) Remove the access platform(s).
B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
Subtask 49-42-51-860-076-A ** ON A/C NOT FOR ALL | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 121VU | APU/APU/CTL | 2KD | L42 |
| 121VU | APU/ECB/SPLY | 1KD | L41 |
C. Aircraft Maintenance Configuration
(1) Put the related hydraulic system in the pressurized configuration (Ref. AMM TASK 29-00-00-864-001).
(2) De-energize the ground service network
(Ref. AMM TASK 24-42-00-862-001).
(3) Remove the WARNING NOTICE(S).
(1) Put the related hydraulic system in the pressurized configuration (Ref. AMM TASK 29-00-00-864-001).
(2) De-energize the ground service network
(Ref. AMM TASK 24-42-00-862-001).
(3) Remove the WARNING NOTICE(S).