W DOC AIRBUS | AMM A320F

Installation of the External Power Contactor (EPC)

TASK 24-41-55-400-001-A
Installation of the External Power Contactor (EPC)

WARNING: MAKE SURE THAT NO AC OR DC POWER IS CONNECTED TO THE AIRCRAFT ELECTRICAL CIRCUITS. THERE IS A RISK OF ELECTROCUTION IF THE AC OR DC POWER STAYS CONNECTED.
ZONE: 212
FIN: 3XG
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)
No specific
Torque wrench: range to between 0.122 and 0.098 m.daN (10.80 and 8.67 lbf.in ) T
No specific
Torque wrench: range to between 0.30 and 0.27 m.daN (26.55 and 23.89 lbf.in ) T
No specific
Torque wrench: range to between 0.60 and 0.50 m.daN (53.10 and 44.25 lbf.in ) T
No specific
Torque wrench: range to between 0.70 and 0.52 m.daN (61.95 and 46.02 lbf.in ) T
No specific
Torque wrench: range to between 1.1 and 0.90 m.daN (97.35 and 79.65 lbf.in ) T
 B. Work Zones and Access Panels
ZONE/ACCESS
ZONE DESCRIPTION
212
COCKPIT
121AL
 C. Referenced Information
REFERENCE
DESIGNATION
TASK 24-23-55-400-001-A
Installation of the APU GLC
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 25-11-41-000-001-A
Removal of the Third Occupant Seat
TASK 25-11-41-400-001-A
Installation of the Third Occupant Seat
F Contactor Base ** ON A/C NOT FOR ALL
F APU/EXT Power-Contactor Module ** ON A/C NOT FOR ALL
F Contactor ** ON A/C NOT FOR ALL
F Contactor ** ON A/C NOT FOR ALL
3. Job Set-up
Subtask 24-41-55-010-051-A
A. Get Access
   (1) Make sure that the Third Occupant seat is removed (Ref. AMM TASK 25-11-41-000-001).
   (2) On the left lower side of panel 120VU, make sure that the access panel (4) is removed.
   (3) Make sure that an access platform is in position at access door 121AL.
   (4) Make sure that access door 121AL is open.
Subtask 24-41-55-860-050-A
B. Aircraft Maintenance Configuration
   (1) Make sure that the external power connector is not connected to the aircraft EXT PWR receptacle.
   (2) Make sure that the warning notice(s) are in position on access door 121AL to tell persons not to connect the external power connector to the aircraft EXT PWR receptacle.
   (3) In the cockpit, on ELEC panel 35VU, make sure that the pushbutton switches that follow are released:
  • BAT 1, BAT 2
  • APU GEN
  • GEN 1, GEN 2
  • EXT PWR.
   (4) In the cockpit, make sure that the WARNING NOTICE(S) are in position to tell persons not to operate the pushbutton switches on the overhead panels that follow:
  • 21VU (EMER ELEC PWR section)
  • 25VU (APU section)
  • 35VU (ELEC).
4. Procedure
Subtask 24-41-55-420-051-A ** ON A/C NOT FOR ALL
A. Installation of the Contactor Base
F Contactor Base ** ON A/C NOT FOR ALL
CAUTION: REFER TO THE MATCH MARKS MADE DURING THE REMOVAL WHEN YOU CONNECT THE ELECTRICAL WIRES. INCORRECT CONNECTION OF THE WIRES WILL CAUSE DAMAGE TO EQUIPMENT.
   (1) Install the contactor base in the correct position, if removed.
   (2) Install the four washers (5) and screws (6) and tighten them.
     (a) TORQUE the four screws (6) to between 0.30 and 0.27 m.daN (26.55 and 23.89 lbf.in ) T.
   (3) Install the three jumpers (3) between the contactor base and the adjacent base.
     (a) Install the six washers (2) and nuts (1) and tighten them.
     (b) TORQUE the six nuts (1) to between 0.70 and 0.52 m.daN (61.95 and 46.02 lbf.in ) T.
   (4) Make sure that the three electrical cables (7) and the six electrical cables (10) are clean and in the correct condition.
   (5) Install the three electrical cables (7).
     (a) Install the three washers (8) and nuts (9) and tighten them.
     (b) TORQUE the three nuts (9) to between 1.1 and 0.90 m.daN (97.35 and 79.65 lbf.in ) T.
   (6) Install the six electrical cables (10).
     (a) Install the three washers (11) and nuts (12) and tighten them.
     (b) TORQUE the three nuts (12) to between 1.1 and 0.90 m.daN (97.35 and 79.65 lbf.in ) T.
Subtask 24-41-55-420-051-B ** ON A/C NOT FOR ALL
A. Installation of the APU/EXT Power-Contactor Module
F APU/EXT Power-Contactor Module ** ON A/C NOT FOR ALL
CAUTION: REFER TO THE MATCH MARKS MADE DURING THE REMOVAL WHEN YOU CONNECT THE ELECTRICAL WIRES. INCORRECT CONNECTION OF THE WIRES WILL CAUSE DAMAGE TO EQUIPMENT.
   (1) Install the APU/EXT power-contactor module (5) in the correct position, if removed.
   (2) Install the eight washers (9) and screws (10) and tighten them.
     (a) TORQUE the nuts (10) to between 0.30 and 0.27 m.daN (26.55 and 23.89 lbf.in ) T.
   (3) Make sure that the electrical cables (3) and (13) and the electrical wires (16) are clean and in the correct condition.
   (4) Install the six electrical cables (3).
     (a) Install the six washers (2) and nuts (1) and tighten them.
     (b) TORQUE the six nuts (1) to between 1.1 and 0.90 m.daN (97.35 and 79.65 lbf.in ) T.
   (5) Install the three electrical wires (16).
     (a) Install the three washers (15) and screws (14) and tighten them.
     (b) TORQUE the three screws (14) to between 0.122 and 0.098 m.daN (10.80 and 8.67 lbf.in ) T.
   (6) Install the six jumpers (6) between the APU/EXT power-contactor module (5) and the adjacent modules.
     (a) Install the twelve washers (7) and screws (8) and tighten them.
     (b) TORQUE the twelve screws (8) to between 0.70 and 0.52 m.daN (61.95 and 46.02 lbf.in ) T.
   (7) Install the three electrical cables (13).
     (a) Install the three washers (12) and screws (11) and tighten them.
     (b) TORQUE the three screws (11) to between 0.70 and 0.52 m.daN (61.95 and 46.02 lbf.in ) T.
   (8) Install the APU GLC (Ref. AMM TASK 24-23-55-400-001).
Subtask 24-41-55-420-050-A
B. Installation of the Contactor
F Contactor ** ON A/C NOT FOR ALL
F Contactor ** ON A/C NOT FOR ALL
   (1) Install the contactor (2) on the six tapped barrels of the contactor base (5).
   (2) TORQUE the six captive screws (3) to between 0.60 and 0.50 m.daN (53.10 and 44.25 lbf.in ) T.
   (3) Remove the blanking caps from the electrical connector (1) and the electrical receptacle (6).
   (4) Make sure that all the electrical connections are clean and in the correct condition.
   (5) Connect the electrical connector (1).
Subtask 24-41-55-710-050-A
C. Test of the External Power Supply
   (1) Make sure that the aircraft electrical circuits are correctly energized with the external power supply (Ref. AMM TASK 24-41-00-861-002).
5. Close-up
Subtask 24-41-55-862-050-A
A. De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
Subtask 24-41-55-410-050-A
B. Close Access
   (1) Make sure that the work area is clean and clear of tools and other items.
   (2) Remove the WARNING NOTICE(S).
   (3) Install the access panel (4) on the panel 120VU.
   (4) Install the third occupant seat (Ref. AMM TASK 25-11-41-400-001).
   (5) Close the access door 121AL.
   (6) Remove the access platform(s).
[Rev.10 from 2021] 2026.03.31 23:24:28 UTC
"Aviabrain" 2025