4.10 SOTF - Switch Onto Fault
In case a faulty line is energized (e. g. when an earthing switch is in closed position), an
instantaneous trip is recommended. The »SOTF« module is active only for a limited period
of time after some selectable condition is fullled:
• With the setting »Enabling« = “Close Command”: activation of SOTF after the circuit•
breaker has been closed manually.
The close command is recognized based on the (rising edge of the) signal »Prot .
SCmd ON«.
• With the setting »Enabling« = “Breaker Pos.”: activation of SOTF with the OPENED•
position of the circuit breaker, and the activation continues until the OPENED
position drops o, plus the timer setting »SOTF . t-enable«. (The breaker positions
are determined according to the principles described in ╚═▷ “Criteria for Determining
the Switchgear Position”.)
A device restart also activates SOTF.
In the special case of a WIC1‑4 with external power supply and current-based
position determination, the CLOSED state is accepted as a SOTF activation only after
the circuit breaker had been OPENED for at least 3 minutes. (This duration is a xed
device-internal time.)
Depending on the setting of »Trigger«, the SOTF condition is recognized by a pickup signal
from one of the phase overcurrent modules or from the peak overcurrent module, or by a
(general) protection pickup.
166 WIC1 WIC1-1.0-EN-MAN
4 Protective Elements
4.10 SOTF - Switch Onto Fault
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