ABB RELION 611 Series Technical Manual page 214

Section 4
Protection functions
208
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Figure 95: Example of INTRPTEF operation in "Intermittent EF" mode in the
faulty feeder, Peak counter limit=3
The timer calculates the start duration value START_DUR which indicates the
percentage ratio of the start situation and the set operating time. The value is available
in the monitored data view.
Timer 2
If the function is used in the directional mode and an opposite direction transient is
detected, the BLK_EF output is activated for the fixed delay time of 25 ms. If the
START output is activated when the BLK_EF output is active, the BLK_EF output is
deactivated.
Blocking logic
There are three operation modes in the blocking function. The operation modes are
controlled by the BLOCK input and the global setting Configuration/System/
Blocking mode which selects the blocking mode. The BLOCK input can be controlled
by a binary input, a horizontal communication input or an internal signal of the
protection relay's program. The influence of the BLOCK signal activation is
preselected with the global setting Blocking mode.
The Blocking mode setting has three blocking methods. In the "Freeze timers" mode,
the operation timer is frozen to the prevailing value. In the "Block all" mode, the whole
1MRS757454 D
611 series
Technical Manual