DOC AIRBUS | TSM A320FElectrical Power to the SLT 1 WTB Monitored to Below 14VDC Electrical Power to the SLT 2 WTB Monitored to Below 14VDC
TASK 27-81-00-810-821-A
Electrical Power to the SLT 1 WTB Monitored to Below 14VDC Electrical Power to the SLT 2 WTB Monitored to Below 14VDC
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 27-81-00-865-057-A
Subtask 27-81-00-810-070-A
Subtask 27-81-00-942-070-A
[Rev.8 from Aug 2018]
2026.04.04 04:27:48 UTC
Electrical Power to the SLT 1 WTB Monitored to Below 14VDC Electrical Power to the SLT 2 WTB Monitored to Below 14VDC
1. Possible Causes
- SLAT/FLAP CONTR.COMP. [21CV]
- SLAT/FLAP CONTR.COMP. [22CV]
A/C wiring/interface between SFCC 1 (2) and the WTB.
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| ASM 246812 | |
| ASM 246813 | |
| AMM 27-51-34-000-001 | Removal of the SFCC |
| AMM 27-51-34-400-001 | Installation of the SFCC |
| AMM 27-81-00-740-002 | BITE Test of the Slat and Flap Control Computers (Slat System) |
| ASM 278101 | |
| ASM 278108 |
Subtask 27-81-00-865-057-A
A. Make sure that this(these) circuit breaker(s) is(are) closed:
Subtask 27-81-00-740-060-A | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C ALL | |||
| 121VU | FLIGHT CONTROLS/WTB/SLT/SYS2 | 11CV | P19 |
| 122VU | FLIGHT CONTROLS/WTB/SLT/SYS1 | 9CV | S06 |
B. SFCC System BITE WTB Power Test
(1) Do a BITE test on the SFCC 1 (2) AMM 27-81-00-740-002. The fault data "WTB electrical power off" is displayed.
(2) Do the fault isolation.
4. Fault Isolation(1) Do a BITE test on the SFCC 1 (2) AMM 27-81-00-740-002. The fault data "WTB electrical power off" is displayed.
(2) Do the fault isolation.
Subtask 27-81-00-810-070-A
A. Procedure
(1) At the circuit breakers:
(a) Examine the C/B for integrity.
(b) Do a check of the A/C HOT BUS 28VDC Supply ASM 246812 ASM 246813.
(c) If the fault is found at steps 4.A.(1)(a) and/or (b), do the repair and do the test at step 3.B.(1).
(2) If the fault continues:
(a) Swap SFCC 1 and SFCC 2
AMM 27-51-34-000-001 and AMM 27-51-34-400-001.
(b) Get access to the SLT ON GROUND FAULTS page and do a check of the ground log.
(c) If the fault moves with SFCC 1(2):
1 Install the serviceable SFCC to its initial position.
2 Replace the defective SLAT/FLAP CONTR.COMP. [21CV] or SLAT/FLAP CONTR.COMP. [22CV] .
(d) If the fault does not move to the other SFCC:
1 Install the SFCCs to their initial positions.
2 Do the next step.
(3) Do the BITE test of the SFCC 1 (2) (Ref. Para.3.A.(1)).
(4) If the fault continues, do a check of theA/C wiring/interface between SFCC 1 (2) and the WTB. ASM 278101 ASM 278108
(5) If there is a wiring/interface fault, do the repair.
(6) Do the BITE test (Ref 3.A.(1)).
5. Close-up(1) At the circuit breakers:
(a) Examine the C/B for integrity.
(b) Do a check of the A/C HOT BUS 28VDC Supply ASM 246812 ASM 246813.
(c) If the fault is found at steps 4.A.(1)(a) and/or (b), do the repair and do the test at step 3.B.(1).
(2) If the fault continues:
(a) Swap SFCC 1 and SFCC 2
AMM 27-51-34-000-001 and AMM 27-51-34-400-001.
(b) Get access to the SLT ON GROUND FAULTS page and do a check of the ground log.
(c) If the fault moves with SFCC 1(2):
1 Install the serviceable SFCC to its initial position.
2 Replace the defective SLAT/FLAP CONTR.COMP. [21CV] or SLAT/FLAP CONTR.COMP. [22CV] .
(d) If the fault does not move to the other SFCC:
1 Install the SFCCs to their initial positions.
2 Do the next step.
(3) Do the BITE test of the SFCC 1 (2) (Ref. Para.3.A.(1)).
(4) If the fault continues, do a check of the
(5) If there is a wiring/interface fault, do the repair.
(6) Do the BITE test (Ref 3.A.(1)).
Subtask 27-81-00-942-070-A
A. Remove the ground support and maintenance equipment, the special and standard tools and all other items.
Subtask 27-81-00-860-071-A B. Put the aircraft back to its initial configuration.