ABB RELION Series, Technical Manual

Page: 653 / 804

SOTF disables any initiation of an autoreclosing shot. The energizing of the power
line is detected from the
CB_POS
information.
SOTF is activated when the AR function is enabled or when the AR function is started
and the SOTF should remain active for the reclaim time.
When SOTF is detected, the parameter SOTF is active.
If the Manual close mode setting is set to FALSE and the circuit
breaker has been manually closed during an autoreclosing shot, the
AR unit goes to an immediate lockout.
If the Manual close mode setting is set to TRUE and the circuit breaker
has been manually closed during an autoreclosing shot (the
INPRO
is
active), the shot is considered as completed.
When SOTF starts, reclaim time is restarted, provided that it is
running.
The frequent-operation counter is intended for blocking the autoreclosing function in
cases where the fault causes repetitive autoreclosing sequences during a short period
of time. For instance, if a tree causes a short circuit and, as a result, there are
autoreclosing shots within a few minutes interval during a stormy night. These types
of faults can easily damage the circuit breaker if the AR function is not locked by a
frequent-operation counter.
The frequent-operation counter has three settings:
• Frq Op counter limit
• Frq Op counter time
• Frq Op recovery time
The Frq Op counter limit setting defines the number of reclose attempts that are
allowed during the time defined with the Frq Op counter time setting. If the set value
is reached within a pre-defined period defined with the Frq Op counter time setting,
the AR function goes to lockout when a new shot begins, provided that the counter is
still above the set limit. The lockout is released after the recovery time has elapsed.
The recovery time can be defined with the
Frq Op recovery time setting .
If the circuit breaker is manually closed during the recovery time, the reclaim time is
activated after the recovery timer has elapsed.
1MRS758755 A
Section 9
Control functions
REC615 and RER615 647
Technical Manual