Instruction manual
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AQ F3x0 Feeder protection IED
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Table 3-47 Setting parameters of the trip logic function
Parameter
Setting value, range
and step
Description
Operation
On
Off
Operating mode selection for the function. Operation can be
either disabled “Off” or enabled “On”.
Default setting is enabled.
Min pulse
length
50…60000 ms by
step of 1 ms
Minimum duration of the generated tripping impulse. Default
setting is 150 ms.
3.3.3
D
EAD LINE DETECTION
The “Dead Line Detection” (DLD) function generates a signal indicating the dead or live
state of the line. Additional signals are generated to indicate if the phase voltages and phase
currents are above the pre-defined limits.
The task of the “Dead Line Detection” (DLD) function is to decide the Dead line/Live line
state.
Criteria of “Dead
line” state: all three phase voltages are b
elow the voltage setting value
AND all three currents are below the current setting value.
Criteria of “Live line” state: all three phase voltages are above the voltage setting value.
Dead line detection function is used in the voltage transformer supervision function also as
an additional condition.
In the figure below is presented the operating logic of the dead line detection function.
