Failure of the DC BUS TIE (Loss of the Connection between the DC BAT Bus and the DC 2 Bus)

TASK 24-60-00-810-804-A
Failure of the DC BUS TIE (Loss of the Connection between the DC BAT Bus and the DC 2 Bus)

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 24-30-00-810-802-A	Failure of the TR2 or TR2 Contactor or Related Wiring
AMM 24-32-00-710-001	Operational Test of the DC Generation Switching
ASM 243502
AMM 24-35-55-000-001	Removal of the Contactor
AMM 24-35-55-400-001	Installation of the Contactor

3. Fault Confirmation
Subtask 24-60-00-710-056-A

A. Test
Do the operational test of the DC generation switching AMM 24-32-00-710-001.

4. Fault Isolation
Subtask 24-60-00-865-050-A

A. Table of the circuit breakers used in this procedure:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
122VU	ELEC/CNTOR/DC BUS/TIE 1/FAULT	14PC	U24

Subtask 24-60-00-810-053-A

B. If the fault symptom is identified by the warnings that follow on the upper ECAM DU:
(1) ELEC TR2 FAULT:

(2) ELEC TR2 FAULT and ELEC DC BUS2 FAULT, and if, on the lower ECAM DU:

The amber DC 2 indication comes into view
The line between the DC 2 and DC BAT buses goes out of view
The ESS TR supplies the DC ESS bus:
. Replace the CNTOR-DC NORM BUS 2 SWITCHING [1PC2] AMM 24-35-55-000-001 and AMM 24-35-55-400-001.

(a) If the fault continues:

Do a check and repair the wiring between:
. The circuit breaker (14PC) pin B/3 of the contactor (1PC2), through the contactors (5PU2, 1PC1, 4PC)
. Pin B/5 of the contactor (1PC2) and the ground ASM 243502.

Subtask 24-60-00-710-057-A

C. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:26:58 UTC