Table. 5.3.5 - 69. Measurement inputs of the I0dir> function.
Signal
Description
Time base
I01RMS
RMS measurement of coarse residual current measurement input I01
5ms
I01TRMS
TRMS measurement of coarse residual current measurement input I01
5ms
I01PP
Peak-to-peak measurement of coarse residual current measurement input I01
5ms
I02RMS
RMS measurement of sensitive residual current measurement input I02
5ms
I02TRMS
TRMS measurement of coarse sensitive current measurement input I02
5ms
I02PP
Peak-to-peak measurement of sensitive residual current measurement input I02
5ms
I0Calc
RMS value of the calculated residual current from the three phase currents
5ms
U0RMS
RMS measurement of zero sequence voltage measurement input U0
5ms
U0Calc
RMS value of the calculated zero sequence voltage from the three phase voltages
5ms
The selection of the used AI channel is made with a setting parameter. In all possible input channel
variations the pre-fault condition is presented with a 20 ms averaged history value from -20 ms from
a START or TRIP event.
General settings
The following general settings define the general behavior of the function. These settings are static i.e.
it is not possible to change them by editing the setting group.
Table. 5.3.5 - 70. General settings of the function.
Name
Description
Range
Step Default
U0
directional
phase
If the connected neutral voltage polarity is opposite to the connected residual
current, this parameter can swap the angle reference.
1: U0
2: -U0
-
1: U0
U0> Meas
input
select
Defines which available neutral voltage measurement is used. Available neutral
voltages depend on measurement settings (
Measurements
→
Transformers
→
VT module).
1: Select
2: U0
Calculated
3: U3
Input
4: U4
Input
-
1:
Select
Measured
magnitude
Defines which available measured magnitude is used by the function. This
parameter is available when "Input selection" has been set to "I01" or "I02".
1: RMS
2: TRMS
3: Peak-
to-peak
-
1: RMS
Input
selection
Defines which measured residual current is used by the function.
1: I01
2: I02
3: I0Calc
-
1: I01
Pick-up
The the pick-up of the I0dir> function is controlled by the
I0
set
setting parameter and the
U0
set
setting
parameter. The former defines the maximum allowed measured current, while the latter defines the
maximum allowed measured voltage and checks the angle difference before action from the function.
The function constantly calculates the ratio between the I0
set
and the
U0
set
and the measured
magnitudes (
I
m
and
U
m
). The reset ratio of 97 % is built into the function and is always relative to the
I0
set
(or
U0
set
) value. When the
I
m
exceeds the
I0
set
value it triggers the pick-up operation of the
function.
A
AQ
Q-G215
-G215
Instruction manual
Version: 2.04
118