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Technical Data
12.9 Directional Overcurrent Protection, Ground
Characteristic curve: see
Minimum time of the characteristic curve
Knee-point time of the curve
Maximum time of the characteristic curve
Knee-point value
Current at minimum time of the curve
Time multiplier
[dwdrloinkn-171013, 1, en_US]
Figure 12-14
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
Instrument current transformer
1458
Figure 12-14
Operate Curve of the Logarithmic Inverse Time with Knee-Point Characteristic (In the Example
of Threshold = 0.004 A)
0.00 s to 30.00 s
0.00 s to 100.00 s
0.00 s to 200.00 s
0.030 A to 35.000 A
0.030 A to 35.000 A
0.05 to 1.50
15 mA sec. (I
= 1 A) or
rated
75 mA sec. (I
= 5 A)
rated
0.5 mA sec. (I
= 1 A) or
rated
2.5 mA sec. (I
= 5 A)
rated
SIPROTEC 5, Overcurrent Protection, Manual
C53000-G5040-C017-8, Edition 07.2017
Increments of 0.01 s
Increments of 0.01 s
Increments of 0.01 s
Increments of 0.001 A
Increments of 0.001 A
Increments of 0.01
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