A070785 V2 ENFigure 304: Functional module diagramTCS statusThis module receives the trip circuit status from the hardware. A detected failure inthe trip circuit activates the timer.TimerOnce activated, the timer runs until the set value of Operate delay time has elapsed.The time characteristic is according to DT. When the operation timer has reachedthe maximum time value, the ALARM output is activated. If a drop-off situationoccurs during the operate time up counting, the fixed 0.5 s reset timer is activated.After that time, the operation timer is reset.The BLOCK input can be controlled with a binary input, a horizontalcommunication input or an internal signal of the relay program. The activation ofthe BLOCK input prevents the ALARM output to be activated.6.1.5 ApplicationTCSSCBR detects faults in the electrical control circuit of the circuit breaker. Thefunction can supervise both open and closed coil circuits. This kind of supervisionis necessary to find out the vitality of the control circuits continuously.Figure 305 shows an application of the trip circuit supervision function use. Thebest solution is to connect an external Rext shunt resistor in parallel with the circuitbreaker internal contact. Although the circuit breaker internal contact is open, TCScan see the trip circuit through Rext. The Rext resistor should have such a resistancethat the current through the resistance remains small, that is, it does not harm oroverload the circuit breaker's trip coil.Section 6 1YHT530004D05 DSupervision functions572 615 seriesTechnical Manual
