HV side
Starpoint
meas,
0:I01
1:I02
-
0:I01
TRF,DIFF
Selection of the starpoint measurement channel for
the HV side restricted earth fault protection. Setting is
visible only if “Enable I0d> (REF) HV side” is set to “1:
Enabled”
Table. 5.4.18. - 154. Settings related to DIF function pre calculation. (continued).
Name
Range
Step Default
Funcs.
Description
Enable I0d>
(REF) LV
side
0:Disabled
1:Enabled
-
0:
Disabled TRF,DIFF LV side restricted earth fault stage enable/disable selection.
LV side
Starpoint
meas,
0:I01
1:I02
-
0:I01
TRF,DIFF
Selection of the starpoint measurement channel for the LV side
restricted earth fault protection. Setting is visible only if “Enable
I0d> (REF) LV side” is set to “1: Enabled”
Table. 5.4.18. - 155. DIF function operating characteristics settings.
Name
Range
Step
Default
Description
Differential
calculation
mode
0:Add
1:Subtract
-
1:Subtract
Calculation mode of the differential current. Depends of the installation
direction of the CT:s and the desired current directions. If both sides
current flow same direction differential current is subtracted, if opposite
then added.
Bias
calculation
mode
0:Average
1:Maximum -
0:Average
Calculation mode of biasing current. With average mode the operation may
be set more sensitive while maximum mode the bias will be always higher
thus giving more stable operation.
Idb>
Pickup
0.01…
100.00%
0.01%
10.00%
Base sensitivity for the differential characteristics
Turnpoint
1
0.01…
50.00xIn
0.01xIn 1.00xIn
Turnpoint 1 for the differential characteristics
Slope 1
0.01…
250.00%
0.01%
10.00%
Slope1 of the differential characteristics
Turnpoint2 0.01…
50.00xIn
0.01xIn 3.00xIn
Turnpoint 2 for the differential characteristics
Slope 2
0.01…
250.00%
0.01%
200.00%
Slope2 of the differential characteristics
Enable
harmonic
blocking
0:No
harm.block
1:2
nd
harm
block
2:5
th
harm
block
3:2
nd
and
5
th
harm
block
-
1:2
nd
harm
block
Selection of the internal blockings to be used for detection of transformer
normal but differential current causing operations.
2
nd
harm
block
pickup
0.01…
50.00%
0.01%
15.00%
Pick-up detection relation (fundamental to harmonic ratio) for 2
nd
harmonic
blocking stage. This setting is visible only if the “Enable harmonic blocking”
setting is set either to 1 or 3 mode.
5
th
harm
block
pickup
0.01…
50.00%
0.01%
35.00%
Pick-up detection relation (fundamental to harmonic ratio) for 5
th
harmonic
blocking stage. This setting is visible only if the “Enable harmonic blocking”
setting is set either to 2 or 3 mode.
Enable
Idi> stage
0:Disabled
1:Enabled
-
1:Enabled
Selection of the non biased and non blocked differential stage enabled or
disabled.
Idi> No
bias
Pickup
200.00…
1500.00%
0.01%
600.00%
Pick-up setting for the non biased/non blocked differential stage. This
setting is visible only if “Enable Idi>” stage is set to 1.
HV I0d>
Pickup
0.01…
100.00%
0.01%
10.00%
Base sensitivity for the HV side restricted earthfault differential
characteristics Setting is visible only if “Enable I0d> (REF) HV side” is set to
“1: Enabled”
AQ-T257
Instruction manual
Version: 2.00
© Arcteq Relays Ltd
176