Measured input values
For the function block is used analog current measurement values from the residual magnitudes.
Residual voltage has to be measured for this function to operate. Either I01 or I02 channel can be
selected for residual current samples.
Table. 5.4.6. - 82. Analogic magnitudes used by the IEF function.
Signal
Description
Time base
U0 samples
U0 residual voltage per unitized samples circular buffer
5 ms
I01 samples
I0 residual current per unitized samples circular buffer
5 ms
I02 samples
I0 residual current per unitized samples circular buffer
5 ms
Selection of the used AI channel is made with a setting parameter.
General settings
The following general settings de ne the general behavior of the function. These settings are static i.e.
it is not possible change them with setting group switching.
Table. 5.4.6. - 83. General settings of the function
Name
Description
Range
Step
Default
Input selection
De nes which measured residual current is used by the function.
1:I01
2:I02
-
1:I01
Pick-up characteristics
Pick-up of the IEF function is controlled by
U0 Detect spike >
and
I0 Detect spike >
setting
parameters, which de ne the maximum allowed measured residual current and voltage before action
from the function. The function constantly calculates the ratio in between of the setting and circular
buffer maximum value.
Table. 5.4.6. - 84. Pick-up characteristics setting
Name
Range
Step
Default
Description
U0 Detect spike >
1.00…100.00%Un
0.01 %Un
80.00%Un
Pick-up setting U0
I0 Detect spike >
0.05…40.00xI0n
0.01 xI0n
0.50 xI0n
Pick-up setting I0
The pick-up activation of the function is not directly equal to start-signal generation of the function.
Start signal is allowed if blocking condition is not active and if the input signal calculated admittance
delta exceeds these settings given admittance threshold. I0 Detect spike > / U0 Detect spike > = set
admittance delta threshold.
Function blocking
In the blocking element the block signal is checked in the beginning of each program cycle. Blocking
signal is received from the blocking matrix for the function dedicated input. If the blocking signal is not
activated when the pick-up element activates, a START signal is generated and the function proceeds
to the time characteristics calculation.
AQ-F255
Instruction manual
Version: 2.00
89
© Arcteq Relays Ltd