2.29 Trip Circuit Supervision
177
7UM61 Manual
C53000-G1176-C127-3
circuit has been interrupted, a short-circuit exists in the trip circuit, battery voltage
failure occurs, or malfunctions occur with the circuit breaker mechanism. Accordingly
it is used as monitoring criterion.
Table 2-8
Condition Table for Binary Inputs, Depending on RTC and CB Position
The conditions of the two binary inputs are scanned periodically. A query takes place
about every 600 ms. If three consecutive conditional checks detect an abnormality
(after 1.8 s), an annunciation is reported (see the following figure). The repeated mea-
surements help to determine the delay of the alarm message and to avoid that an
alarm is output during short-time transition periods. After the fault in the trip circuit is
removed, the alarm is reset automatically after the same time.
Figure 2-68
Logic diagram of the trip circuit supervision with two binary inputs
Monitoring with
Two Binary Inputs
(connected to
common potential)
If two binary inputs connected to common potential are used, they are connected ac-
cording to Figure 2-67, to L+ or once in parallel with the corresponding protection
command relay contact and to the circuit breaker auxiliary contact 1.
Figure 2-69
Principle of Trip Circuit Monitor with Two Binary Inputs (connected to common
potential)
No.
Trip contact
Circuit breaker
AuxCont 1
AuxCont 2
BI 1
BI 2
1
Open
TRIP
Closed
Open
H
L
2
Open
CLOSE
Open
Closed
H
H
3
Closed
TRIP
Closed
Open
L
L
4
Closed
CLOSE
Open
Closed
L
H
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