8.2.7.3 Blocking
It is possible to block two step overvoltage protection (OV2PTOV ,59) partially or
completely, by binary input signals where:
BLOCK: blocks all outputs
BLK1: blocks all pickup and trip outputs related to step 1
BLK2: blocks all pickup and trip outputs related to step 2
8.2.7.4 Design
The voltage measuring elements continuously measure the three phase-to-ground
voltages or the three phase-to-phase voltages. Recursive Fourier filters filter the input
voltage signals. The phase voltages are individually compared to the set value, and the
highest voltage is used for the inverse time characteristic integration. A special logic is
included to achieve the 1 out of 3, 2 out of 3 or 3 out of 3 criteria to fulfill the PICKUP
condition. The design of Two step overvoltage protection (OV2PTOV, 59) is
schematically described in
Figure 54.
1MRK 505 277-UUS C Section 8
Voltage protection
135
Technical Manual
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