Siemens SIPROTEC 7SD610 Manual page 159

Figure 2-60 Logic diagram of the overvoltage protection for zero sequence voltage
Freely selectable single-phase voltage
As the zero-sequence voltage stages operate separately and independently of the other protection overvoltage
functions, they can be used for any other single-phase voltage. Therefore the fourth voltage input U
device must be assigned accordingly (also see Section 2.1.2, „Voltage Transformer Connection").
The stages can be blocked via a binary input „>3U0>(>) BLK". Internal blocking is not accomplished in this
application case.
SIPROTEC, 7SD610, Manual
C53000-G1176-C145-6, Release date 02.2011
2.11 Undervoltage and Overvoltage Protection (optional)
Functions
of the
4
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