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Applications
Example1 (Figure 10.3-2) shows BI1 and BI2 signals are connected at "TC1_FAIL_SIGNAL1"
and "TC1_FAIL_SIGNAL2". When trip circuit is healthy, small current will flow on BI circuits†,
CB auxiliary contacts, and trip coil. We can observe the small current when CB is open or CB
are closed. If the current dose not flow, or if there is open circuit between trip and BI circuits,
signal "TC1_FAIL" will be generated. Consequently, TCS1 logic will issue an alarm 'Trip
Circuit Fail'.
Trip circuit
( + )
Protection
relay
52a
52b
Trip coil
( − )
LCP & GIS
†Note: Threshold should be set on BI circuits. The value should be set for 50% trip supply
voltage, because there are two series BI circuits. Supply voltage over BI circuits is
half when 52a contact is closed and 52b contact is open. BI circuit cannot operate
if BI sensitivity is equal to the supply voltage. That is, we need to set BI threshold
voltage below 55V when trip supply voltage is 110V.
Example2 (Figure 10.3-3) shows a BI signal is connected with "TC1_FAIL_SIGNAL1". With
the arrangement if CB is open, small monitoring current will not flow on BI circuit. Therefore,
we need to set OPT-On for the switch [TCS1-EN]; CB-closed-status signal should be connected
with PLC connection point "TC1_FAIL_COND". Current can be monitored during CB is closed,
if OPT-On is set. This can avoid unnecessary monitoring when CB is open.
R
Binary input
BI1
circuit
R
Binary input
BI2
circuit
800001EBB2
TC1_FAIL_COND
Figure 10.3-2 TCS example1
- 841 -
8000011BB0
800001EBB0
TC1_FAIL_SIGNAL1
8000011BB1
800001EBB1
TC1_FAIL_SIGNAL2
8000011BB2
&
OPT-On
TCS1-EN
On
6F2T0207 (0.01)
1
&
8000011B60
t 0
0 t
TC1_FAIL
1
0.4s
0.4s
≥1
GRE200 (5,6)
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