U1<ST1TR1tReset1t1IEC10000040-3-en.vsdIEC10000040 V3 ENFigure 247: Example for Definite Time Delay stage 1 operation9.3.7.3 BlockingIt is possible to block Two step residual overvoltage protection ROV2PTOV partiallyor completely, by binary input signals where:BLOCK: blocks all outputsBLKTR1: blocks all trip outputs of step 1BLKST1: blocks all start and trip outputs related to step 1BLKTR2: blocks all trip outputs of step 2BLKST2: blocks all START and trip inputs related to step 29.3.7.4 DesignThe voltage measuring elements continuously measure the residual voltage.Recursive Fourier filters filter the input voltage signal. The single input voltage iscompared to the set value, and is also used for the inverse time characteristicintegration. The design of Two step residual overvoltage protection (ROV2PTOV) isschematically described in figure 248.Section 9 1MRK502052-UEN BVoltage protection514Technical manual
