It is possible to monitor trip circuit with latched output contact but then monitoring the trip circuit is
possible only while the circuit breaker status is closed. Whenever the breaker is open the TCS is
blocked by an internal logic scheme. The disadvantage is that you don’t know whether the trip circuit is
intact or not when the breaker is closed again.
While the circuit breaker is in open position the TCS alarm is blocked by using following logic scheme
or similar. TCS alarm is giving whenever the breaker is closed and inverted digital input signal (TCS)
activates. Normally closed digital input activates only when there is something wrong in the trip circuit
and the auxiliary power goes off. While the breaker is open the logic is blocked. Logical output can be
used in output matrix or in SCADA as pleased.
Figure. 7.3. - 173. TCS block scheme when non-latched trip output is not used.
AQ-T257
Instruction manual
Version: 2.00
307
© Arcteq Relays Ltd