Functions
2.5 Under and over-voltage protection (optional)
SIPROTEC, 7VK61, Manual
C53000-G1176-C159-3, Release date 05.2009
103
Figure 2-25
Logic diagram of the undervoltage protection for phase voltages
Phase-phase undervoltage
Basically, the phase-phase undervoltage protection operates like the phase-earth protection except that it
detects phase-to-phase voltages. Accordingly, both phases are indicated during pickup of an undervoltage
stage if one of the stage thresholds
Uph-ph<
or
Uph-ph<<
was undershot. Beyond this, Figure 2-25 applies
in principle.
It is sufficient for the current criterion that current flow is detected in one of the involved phases.
Summary of Contents for Siprotec 7VK61
Page 8: ...Preface SIPROTEC 7VK61 Manual C53000 G1176 C159 3 Release date 05 2009 8 ...
Page 14: ...Contents SIPROTEC 7VK61 Manual C53000 G1176 C159 3 Release date 05 2009 14 ...
Page 316: ...Literature SIPROTEC 7VK61 Manual C53000 G1176 C159 3 Release date 05 2009 316 ...
Page 328: ...Glossary SIPROTEC 7VK61 Manual C53000 G1176 C159 3 Release date 05 2009 328 ...