W DOC AIRBUS | TSM A320F

Abnormal Electrical Transient Time on AC 1 busbar during Switching from IDG 1 or External Power to APU Generator

TASK 24-23-00-810-828-A
Abnormal Electrical Transient Time on AC 1 busbar during Switching from IDG 1 or External Power to APU Generator

1. Possible Causes
  • MODULE DIODE UNIT [1164VD]
  • wiring
  • RELAY-APU AVAIL [6KD]
  • GCU-APU [1XS]
  • RELAY-GLC 1 AUX CTL [4XU1]
  • GLC-1 [9XU1]
  • BTC-1 [11XU1]
  • RELAY-EPC AUX CTL [5XG]
  • EPC [3XG]
  • GLC-APU [3XS]
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AMM 24-22-55-000-001
Removal of the Contactors
AMM 24-22-55-400-002
Installation of the Contactors
ASM 242302
AWM 242304
AMM 24-23-34-000-001
Removal of the GCU-APU
AMM 24-23-34-400-001
Installation of the GCU-APU
AMM 24-23-55-000-001
Removal of the APU GLC
AMM 24-23-55-400-001
Installation of the APU GLC
AMM 24-41-00-861-002
Energize the Aircraft Electrical Circuits from the External Power
AMM 24-41-55-000-001
Removal of the External Power Contactor (EPC)
AMM 24-41-55-400-001
Installation of the External Power Contactor (EPC)
AMM 31-60-00-860-001
EIS Start Procedure
AMM 49-00-00-860-003
APU Start by External Power
AMM 49-00-00-860-005
APU Start by External Power
AMM 49-00-00-860-008
APU Start by External Power
AMM 71-00-00-710-003
Engine Automatic Start
3. Fault Confirmation
Subtask 24-23-00-860-069-A ** ON A/C NOT FOR ALL
A. Aircraft Maintenance Configuration
   (1) Energize the aircraft electrical circuits from the external power AMM 24-41-00-861-002.
   (2) Do the EIS start procedure (Upper ECAM DU and lower ECAM DU only)
AMM 31-60-00-860-001.
   (3) Start the APU:
Subtask 24-23-00-710-061-A ** ON A/C NOT FOR ALL
B. Test
   (1) On the ELEC panel 35VU, release the BAT1 and BAT2 pushbutton switches:
  • The OFF legend comes on.
   (2) On the ELEC panel 35VU, push the EXT PWR pushbutton switch:
  • The ON legend goes off.
  • The AVAIL legend comes on.
   (3) Make sure that the fault continues.
   (4) On the ELEC panel 35VU, push the EXT PWR pushbutton switch:
  • The ON legend comes on.
  • The AVAIL legend goes off.
   (5) On the ELEC panel 35VU, push the BAT1 and BAT2 pushbutton switches:
  • The OFF legend goes off.
   (6) On the ELEC panel 35VU, push the EXT PWR pushbutton switch:
  • The ON legend goes off.
  • The AVAIL legend comes on.
   (7) If the fault stops, go to Para. 4.A.
   (8) If the fault continues, go to Para. 4.B.
Subtask 24-23-00-710-061-C ** ON A/C NOT FOR ALL
B. Test
   (1) On the ECAM control panel, push the ELEC key (on the lower ECAM DU, the ELEC page comes into view).
  • Make sure that the APU energizes the aircraft electrical circuit correctly.
   (2) On the ELEC panel 35VU, make sure that the BAT1 and BAT2 pushbutton switches are pushed:
  • The OFF legends are off.
   (3) Make sure that on the ELEC page on the lower ECAM DU:
  • The green arrow from the DC BAT indication to the BAT 1 or the green line between the DC BAT indication and the BAT 1 is shown.
  • The green arrow from the DC BAT indication to the BAT 2 or the green line between the DC BAT indication and the BAT 2 is shown.
   (4) On the ELEC panel 35VU, release the EXT PWR pushbutton switch:
  • The ON legend goes off.
  • The AVAIL legend comes on.
   (5) If the fault stops, go to Para. 4.A.
   (6) If the fault continues (long time with signifiant impacts in the cockpit), go to Para. 4.B.
4. Fault Isolation
Subtask 24-23-00-810-081-C ** ON A/C NOT FOR ALL
A. If the fault stops:
   (1) Replace the MODULE DIODE UNIT [1164VD] .
   (2) If the fault continues:
     (a) Do a check of the wiring AWM 242304 between:
  • Pin D module 34 of the terminal block 1156VT and pin 44 of the diode module (1164VD) through the APU AVAIL relay (6KD)
  • Pin S module 31 of the terminal block 1154VT and pin 43 of the diode module (1164VD).
       1 If the wiring is correct:
  • Replace the RELAY-APU AVAIL [6KD] .
       2 If the wiring is not correct:
  • Repair it.
Subtask 24-23-00-810-082-B ** ON A/C NOT FOR ALL
B. If the fault continues:
   (1) Replace the RELAY-GLC 1 AUX CTL [4XU1] .
   (2) If the fault continues:
Subtask 24-23-00-810-081-G ** ON A/C NOT FOR ALL
C. If the fault stops:
   (1) On ELEC panel 35VU, push the EXT PWR pushbutton switch:
  • The ON legend comes on.
  • The AVAIL legend goes off.
   (2) On ELEC panel 35VU:
     (a) Release the BAT1 and BAT2 pushbutton switches:
  • The OFF legends come on.
     (b) Push the BAT1 and BAT2 pushbutton switches:
  • The OFF legends go off.
   (3) On the ELEC, page on the lower ECAM DU, after few seconds:
  • The green arrow from the DC BAT indication to the BAT 1 or the green line between the DC BAT indication and the BAT 1 goes out of view.
  • The green arrow from the DC BAT indication to the BAT 2 or the green line between the DC BAT indication and the BAT 2 goes out of view.
   (4) On ELEC panel 35VU, release the EXT PWR pushbutton switch:
  • The ON legend goes off.
  • The AVAIL legend comes on.
     (a) If the fault continues:
       1 If the fault continues:
  • Do a check and repair the wiring ASM 242302 between:
    . Pin AA/12D of the APU GCU (1XS) and pin D3 of the external-power control relay (5XG)
    . Pin AA/2D of the APU GCU (1XS) and the first terminal block.
     (b) If the fault stops:
  • Start the engine 1 AMM 71-00-00-710-003.
  • On the lower ECAM DU, on the ELEC page, make sure that there is a green line between the GEN1 indication and the AC1 busbar.
  • On the lower ECAM DU, on the ELEC page, make sure that:
    . The green arrow from the DC BAT indication to BAT 1 or the green line between the DC BAT indication and BAT 1 are not shown.
    . The green arrow from the DC BAT indication to BAT 2 or the green line between the DC BAT indication and BAT 2 are not shown.
  • On the ELEC control panel 35VU:
    . Release the GEN1 pushbutton switch.
    . The OFF legend of the GEN1 pushbutton switch comes on.
       1 If the fault continues:
  • Replace RELAY-GLC 1 AUX CTL [4XU1] .
         a If the fault continues:
Subtask 24-23-00-810-082-C ** ON A/C NOT FOR ALL
D. If the fault continues:
   (1) Replace the RELAY-EPC AUX CTL [5XG] .
   (2) If the fault continues:
   (3) If the fault continues:
[Rev.8 from Aug 2018] 2026.04.04 04:26:42 UTC
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