Directional Overcurrent Protection, Ground
Stage with Definite-Time Characteristic Curve
Setting Values for the Function Direction Determination
Method for direction determination Zero sequence
Negative sequence
–
Minimum V0 or V2 threshold 0.150 V to 20.000 V 0.001 V
Rotation angle of the reference voltage -180° to 180° 1°
Forward range 0° to 180° 1°
Setting Values
Direction mode Forward
Reverse
–
Method of measurement Fundamental component
RMS value
–
Threshold value 1 A @ 100 Irated 0.030 A to 35.000 A Increments of 0.001 A
5 A @ 100 Irated 0.15 A to 175.00 A Increments of 0.01 A
Dropout ratio 0.90 to 0.99 Increments of 0.01
Operate delay 0.00 s to 60.00 s Increments of 0.01 s
Dropout delay 0.00 s to 60.00 s Increments of 0.01 s
Dropout
The greater dropout differential (= | pickup value – dropout value |) of the following 2 criteria
applies:
Dropout differential derived from the parameter
Dropout ratio
If this parameter is not available, a dropout ratio of 95 % applies for overcurrent and of 105 % for undercur-
rent functionality.
Minimum absolute dropout differential
Protection-class current transformer 15 mA sec. (I
rated
= 1 A) or
75 mA sec. (I
rated
= 5 A)
Instrument current transformer 0.5 mA sec. (I
rated
= 1 A) or
2.5 mA sec. (I
rated
= 5 A)
Times
The maximum pickup time with operate delay = 0 ms
Approx. 30 ms + OOT at 50 Hz
Approx. 25 ms + OOT at 60 Hz
Extension of the operate time during operation with
inrush-current detection
Approx. 10 ms
Dropout time Approx. 20 ms + OOT
11.18
11.18.1
Technical Data
11.18 Directional Overcurrent Protection, Ground
952 SIPROTEC 5, Low-Impedance Busbar Protection, Manual
C53000-G5040-C019-C, Edition 04.2021
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