Unwanted Tripping of a Circuit Breaker on the AC/DC Emergency Power Center

TASK 31-54-00-810-926-A
Unwanted Tripping of a Circuit Breaker on the AC/DC Emergency Power Center

1. Possible Causes

defective circuit breaker

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 315406
AMM 31-60-00-860-001	EIS Start Procedure
AMM 31-60-00-860-002	EIS Stop Procedure

3. Fault Confirmation
Subtask 31-54-00-860-058-A

A. Do the EIS start procedure (upper ECAM DU and lower ECAM DU only) AMM 31-60-00-860-001.

Subtask 31-54-00-710-286-A

B. Test
Make sure that a warning is shown on the upper ECAM DU.

4. Fault Isolation
Subtask 31-54-00-810-175-A

A. If the upper ECAM DU gives the warning message C/B TRIPPED L ELEC BAY:

do a check of the status of the circuit breakers on the AC/DC emergency power center (106VU).

(1) If all the circuit breakers are closed:

do a check for correct continuity between pin 3 (GND signal) and pin 4 for each of these circuit breakers on AC/DC emergency power center (106VU) ASM 315406.
replace the defective circuit breaker .

(2) If one circuit breaker or more is (are) open:

NOTE: On ground you must not close a tripped circuit breaker without trouble shooting of the related system.

(a) Do an isolation check of the wiring between the C/B and the related system.
1 If there is an isolation fault:

repair the wiring between the C/B and the related system.
Close the tripped circuit breaker(s).

Subtask 31-54-00-860-059-A

B. Do the EIS start procedure given in Para. 3.A.
(1) Make sure that the warning message is no longer shown.
(2) Do the EIS stop procedure AMM 31-60-00-860-002.

[Rev.8 from Aug 2018] 2026.04.04 04:30:32 UTC