Trip Circuit Supervision; Trip Circuit Supervision By 1 Binary Input; Supervision Scheme Logic - Toshiba GRE110 Instruction Manual

3.3.3 Trip Circuit Supervision

The circuit breaker tripping control circuit can be monitored by either one or two binary inputs, as
described below.

Trip Circuit Supervision by 1 binary input

The circuit breaker tripping control circuit can be monitored by one binary input. Figure 3.3.1
shows a typical scheme. When the trip circuit is complete, a small current flows through the binary
input, the circuit breaker auxiliary contacts and the trip coil. This current flows for both the breaker
open and closed conditions. Then logic signal output of the binary input circuit TC FAIL is "1"
under healthy conditions.
If the trip supply is lost or if a connection becomes an open circuit, then the binary input resets and
TC FAIL becomes "0". Figure 3.3.2 shows the scheme logic. A trip circuit fail alarm TCSV is
output when TC FAIL is "0".
The monitoring is enabled by setting the scheme switch [TCSPEN] to "ON" or "OPT-ON" and the
one BI selected "TCFAIL". When "OPT-ON" is selected, the monitoring is enabled only while CB
is closed.
+ve
Trip
Supply
(BI command)
(BI command)
CB status "closed"
[TCSPEN]
+
Trip Circuit Supervision by 2 binary inputs
The circuit breaker tripping control circuit can be monitored by two binary inputs. Figure 3.3.3
shows a typical scheme. When the trip circuit is complete, a small current flows in photo-couplers,
the circuit breaker auxiliary contacts and the trip coil. This current flows for both the breaker open
and closed conditions.
If the trip circuit supply is lost or if a connection becomes open circuit then the TCS issues a Trip
Circuit Fail alarm.
GRE110
Trip Output
Binary
Input
Figure 3.3.1 Trip Circuit Supervision by 1 binary input
TC FAIL
≥1
TC FAIL
≥1
&
"OPT-ON"
"ON"
Figure 3.3.2 Supervision Scheme Logic
 71 
Circuit Breaker
CB Trip Coil
CB Aux.
Contacts
0
t 0
1
&
0.4s
6 F 2 T 0 1 7 2
-ve Trip
Supply
t
TCSV
0.4s