Failure of the DC BUS TIE (Loss of the Connection between the DC BUS 1, DC BAT BUS and DC BUS 2)

TASK 24-60-00-810-812-A
Failure of the DC BUS TIE (Loss of the Connection between the DC BUS 1, DC BAT BUS and DC BUS 2)

1. Possible Causes

RELAY-SWTG SPLY/TR 1 FAULT [8PC1]
wiring
C/B-ELEC/TR1/FAULT/DC BUS TIE/CONFIG [7PC1]

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 24-32-00-710-001	Operational Test of the DC Generation Switching
ASM 243502
AMM 24-41-00-861-002	Energize the Aircraft Electrical Circuits from the External Power
AMM 24-41-00-862-002	De-energize the Aircraft Electrical Circuits Supplied from the External Power
AMM 31-60-00-860-001	EIS Start Procedure

3. Fault Confirmation
Subtask 24-60-00-860-068-A

A. Job Set-up
(1) Aircraft Maintenance Configuration
(a) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
(b) Do the EIS start procedure (Upper ECAM DU and lower ECAM DU only)
AMM 31-60-00-860-001.

Subtask 24-60-00-710-072-A

B. Test
(1) Do this test:

ACTION	RESULT
On the ECAM control panel: push the ELEC key to get the ELEC page.	On the upper ECAM display unit: the ELEC TR1 FAULT, ELEC DC BUS 1 FAULT and ELEC DC BAT BUS FAULT warnings come into view.
	On the lower ECAM display unit: the DC1 and DC BAT indications come on amber the line between the DC 2 and DC BAT busses goes off the line between the DC 1 and DC BAT busses goes off the DC ESS bus is supplied by the ESS TR.

4. Fault Isolation
Subtask 24-60-00-865-058-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
122VU	ELEC/TR1/FAULT/DC BUS TIE/CONFIG	7PC1	W29

Subtask 24-60-00-810-061-A

B. If the fault continues:

Replace the RELAY-SWTG SPLY/TR 1 FAULT [8PC1] .

(1) If the fault continues:

Do a check of the status of the circuit breaker (7PC1).

(a) If the circuit breaker is closed:

Do a check and repair the wiring between:
. the circuit breaker (7PC1) and the pins A/X1 and A/B2 of the relay (8PC1)
. the pin A/B1 of this relay and the pins B/3 of the contactors (1PC1) and (1PC2), through the relays (20XN1, 20XN2) and the contactor (4PC)
. the pin B/5 of the contactors (1PC1) and (1PC2) and the ground ASM 243502.

(b) If the circuit breaker is open:

Do the procedure (Ref. TSM TASK 24-00-00-810-803).

1 If the fault continues:

Replace the C/B-ELEC/TR1/FAULT/DC BUS TIE/CONFIG [7PC1] .

Subtask 24-60-00-710-073-A

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

5. Close-up
Subtask 24-60-00-860-069-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.
(2) De-energize the aircraft electrical circuits
AMM 24-41-00-862-002.

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