Self-Diagnosis - Mitsubishi Electric CBV2-A01D1 Instruction Manual

4.3 Self-diagnosis

The self-diagnosis function monitors the electronic circuit and built-in power source continuously. If an
abnormal condition occurs, the protection elements will be locked for operation. Also, the RUN LED lamp
will go off and the self-diagnosis output contact (break contact) will be closed.
(1) Checking defect code at failure detection
When a failure is detected, the defect code will be recorded. This defect code can be checked
through the self-diagnosis (ALARM) status indication.
(2) Resetting self-diagnosis output
If a failure is detected, the failure status may be reset by turning off/on the power.
In this case, be sure to lock the trip circuit on the external wiring of the relay before resetting. (If
the failure persists, an erroneous output may be caused).
(3) Clearing the defect code
The defect code data stored at failure detection can not be cleared only by carrying out the power
on/off procedure in the item (2) above. All the defect code numbers that have been detected since
the previous "self-diagnosis reset" (RESET ALARM) operation was made are accumulated in the
memory. To clear the record data, carry out "self-diagnosis reset" (RESET ALARM) operation.
Status
Normal
Power circuit
failure
CPU failure
ROM check
RAM check
A/D accuracy check
A/I check
A/D check
SRAM check
D/O status check
D/O operation check
Analog filter check
A/I double check
Monitor
D/I check
error
2
E PROM check
Computing function check
WDT check
Data transfer check
Differential current check
Communication card check
Communication card channel No. switch setting error
Communication card portrait switch setting error
Communication card channel No. switch change error
Communication card portrait switch change error
41 Monitored only in the models with built-in D/I function.
＊
42 Monitored only in the models with D2 unit.
＊
43 Monitored only the biased differential relay.
＊
44 Monitored only when the relay is installed with communication card.
＊
Table 4.1 Output for protection relay failures
Detected items
−
−
−
Display
RUN
On
Off
＊41
＊42
＊43
＊44
＊44
On
＊44
＊44
＊44
14
Output
ALARM
Operation
(break
Defect
output lock
contact)
code
Open Not locked
No
Locked
display
Not locked
0001
0002
0003
0004
0005
0006
0008
Closed
0009
Locked
0010
0011
0012
0013
0014
0015
0016
0017
0028
0029
0030 Open Not locked
0031
0032
PCKN-OIL738