W DOC AIRBUS | TSM A320F

Failure of the Manual Switching Circuit of the AC Essential Bus

TASK 24-50-00-810-805-A
Failure of the Manual Switching Circuit of the AC Essential Bus

1. Possible Causes
  • CNTOR-AC ESS BUS SWITCHING [3XC]
  • wiring
  • P/BSW-ELEC/AC ESS FEED [11XC]
  • RELAY-EMER CONDITION (12XE)
  • CNTOR-AC ESS BUS SWITCHING [15XE]
  • C/B-AC ESS/BUS ON/BUS 2 [2XC]
  • C/B-AC ESS BUS/STBY/CNTOR/CTL [5XC]
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
TSM TASK 24-00-00-810-803-A
Circuit Breaker Tripped and/or C/B TRIPPED Warning
AMM 24-24-55-000-002
Removal of the AC ESS BUS Contactor
AMM 24-24-55-400-002
Installation of the AC ESS BUS Contactor
AMM 24-25-00-710-001
Operational Test of the AC Essential-Generation Switching
ASM 242501
AMM 24-25-55-000-001
Removal of the AC Essential Bus Switching Contactor
AMM 24-25-55-400-001
Installation of the AC Essential Bus Switching Contactor
3. Fault Confirmation
Subtask 24-50-00-710-058-A
A. Test
Do the operational test of the AC essential generation switching AMM 24-25-00-710-001.
4. Fault Isolation
Subtask 24-50-00-810-054-A
A. If the test confirms the fault:
  • Do a check for 115VAC between the pins A/K and A/L of the AC essential bus switching contactor (3XC) ASM 242501.
   (1) If there is 115VAC:
   (2) If there is no 115VAC:
  • Do a check of the status of the circuit breaker (5XC).
     (a) If the circuit breaker (5XC) is closed:
  • Do a check for 115VAC at the pin 2 of the circuit breaker (5XC).
       1 If there is 115VAC:
       2 If there is no 115VAC:
  • Do a check of the status of the circuit breaker (2XC).
         a If the circuit breaker (2XC) is closed:
  • Do a check and repair the wiring between:
    . the pins A2, B2, C2 of the circuit breaker (2XC) and the pins T1, T2, T3 of the contactor (3XC)
    . the pin T3 of the contactor (3XC) and the pin 1 of the circuit breaker (5XC) ASM 242501
         b If the circuit breaker (2XC) is open:
     (b) If the circuit breaker (5XC) is open:
       1 If the fault continues:
  • Do a check of the wiring for short to ground between respectively:
    . the pin 2 of the circuit breaker (5XC) and the pin A/N of the contactor (3XC)
    . the pin 2 of the circuit breaker (5XC) and the pin A/K of the contactor (3XC), through all the components given in Para. 4.A.(2)(a)1_ ASM 242501.
         a If the wiring is not correct:
  • Repair the wiring .
         b If the wiring is correct:
  • Replace the C/B-AC ESS BUS/STBY/CNTOR/CTL [5XC] .
Subtask 24-50-00-710-059-A
B. Do the test given in Para. 3.
[Rev.8 from Aug 2018] 2026.04.04 04:26:56 UTC
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