DOC AIRBUS | TSM A320FLoss of the Aircraft 28 Volt Supply to the EEC 1
1. Possible Causes
· EIU-1 ( 1KS1 )
· wiring
· EEC ( 4000KS )
2 Job Set-up Information
A. Referenced Information
REFERENCE DESIGNATION
Ref. AMM 24-41-00-861-002 Energize the Aircraft Electrical Circuits from the External Power
Ref. AMM 24-41-00-862-002 De-energize the Aircraft Electrical Circuits Supplied from the External
Power
Ref. AMM 31-60-00-860-001 EIS Start Procedure
Ref. AMM 31-60-00-860-002 EIS Stop Procedure
REFERENCE DESIGNATION
Ref. AMM 71-13-00-010-010 Opening of the Fan Cowls 437AL(447AL),438AR(448AR)
Ref. AMM 71-13-00-410-010 Closing of the Fan Cowls 437AL(447AL),438AR(448AR)
Ref. AMM 73-22-00-710-040 Operational Test of the FADEC SYSTEM on the Ground
Ref. AMM 73-22-34-000-010 Removal of the Electronic Engine Control (EEC)
Ref. AMM 73-22-34-400-010 Installation of the Electronic Engine Control (EEC)
Ref. ASM 73-25-05
Ref. AMM 73-25-34-000-041 Removal of the Engine Interface Unit (EIU)
Ref. AMM 73-25-34-400-041 Installation of the Engine Interface Unit (EIU)
Aircraft 28 Volt Supply (Engine 1) SHEET 1
Figure 73(IAE)-00-00-991-01700-A / SHEET 1/1 - Aircraft 28 Volt Supply (Engine 1) not printed, as per
printing preferences
3. Fault Confirmation
Subtask 73-00-00-860-134-A
A. Job Set-Up
(1) Energize the aircraft electrical circuits
Ref. AMM 24-41-00-861-002 .
(2) Do the EIS start procedure (Upper ECAM DU and lower ECAM DU only)
Ref. AMM 31-60-00-860-001 .
Subtask 73-00-00-710-144-A
B. Test
(1) Do the operational test of the FADEC system (FADEC 1A and 1B) on the ground Ref.
AMM 73-22-00-710-040 .
(a) Make a record of the FADEC 1A or FADEC 1B channel which found the fault.
4. Fault Isolation
(Ref. Fig. Aircraft 28 Volt Supply (Engine 1) SHEET 1)
Subtask 73-00-00-865-050-A
A. Table of the circuit breakers used in this procedure:
PANEL DESIGNATION FIN LOCATION
49VU ENGINE/1/FADEC A/AND EIU 1 2KS1 A04
121VU ENGINE/ENG1/FADEC B/AND EIU 1 4KS1 R41
Subtask 73-00-00-810-098-B
B. If the test gives the maintenance message A/C 28V POWER/EEC1:
· on the ECAM control panel, push the ENG key to get the ENGINE page
· on the SD, the ENGINE page comes into view.
(1) If the oil temperature indications are not shown on the ENGINE page:
· do a check for 28VDC at the EIU-1 (1KS1) pins AC/9, 11 Ref. ASM 73-25-05.
(a) If there is 28VDC at each pin:
· replace the EIU-1 ( 1KS1 ) Ref. AMM 73-25-34-000-041 and Ref. AMM 73-25-34-400-041 .
(b) If there is no 28VDC:
· repair the wiring between the EIU-1 (1KS1) and the circuit breakers (2KS1 and 4KS1) Ref.
ASM 73-25-05.
(2) If the oil temperature indications are shown on the ENGINE page:
· open the fan cowls 437AL and 438AR Ref. AMM 71-13-00-010-010 .
(a) If the channel which found the fault (during the test) was FADEC 1A and the fault continues:
· do a check and repair wiring :
. from the EEC (4000KS) pin J3/m to the EIU-1 (1KS1) pin AC/7
. from the EEC (4000KS) pin J3/r to the ground module (4023VN) Ref.
ASM 73-25-05.
(b) If the channel which found the fault (during the test) was FADEC 1B and the fault continues:
· do a check and repair the wiring :
. from the EEC (4000KS) pin J9/m to the EIU-1 (1KS1) pin AC/2
. from the EEC (4000KS) pin J9/r to the ground module (4001VN) Ref.
ASM 73-25-05.
(3) If the fault continues:
· replace the EEC ( 4000KS ) Ref. AMM 73-22-34-000-010 and Ref. AMM 73-22-34-400-010 .
Subtask 73-00-00-710-145-A
C. Do the test given in Para. 3.
5. Close-up
Subtask 73-00-00-860-135-A
A. Put the aircraft back to its initial configuration.
(1) On the ECAM control panel, set the UPPER DISPLAY and LOWER DISPLAY potentiometers to OFF.
Ref. AMM 31-60-00-860-002 .
(2) On the panel 50VU, push the ENG/FADEC GND PWR/1 pushbutton switch.
(3) De-energize the aircraft electrical circuits
Ref. AMM 24-41-00-862-002 .
(4) Make sure that the fan cowls 437AL and 438AR are closed Ref. AMM 71-13-00-410-010 . [Rev.6 from Feb 2017] 2026.04.04 04:36:05 UTC