Siemens SIPROTEC 4 7UT6 Series Manual page 263

[broken-wire-logic-230508-he, 2, en_GB]
Figure 2-122
Detection of a broken wire is restricted by technical limits. A broken wire in the secondary circuit can, of
course, only be detected when a steady state current has been flowing through the respective phase. Further-
more, a wire break at the instant of zero crossing in current cannot always be detected reliably. No expected
value can be calculated when the frequency is out of the operation frequency (f
Note that electronic test devices do not simulate the correct behaviour of broken wire so that pickup may
occur during such tests.
SIPROTEC 4, 7UT6x, Manual
C53000-G1176-C230-5, Edition 09.2016
Logic of the Broken Wire Detection
Functions
2.19 Monitoring Functions
± 10 %).
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