Technical Data
4.16 Ground Fault Protection 64, 67N(s), 50N(s), 51N(s)
SIPROTEC, 7SJ62/64, Manual
C53000-G1140-C207-2, Release date 01.2008
515
Angle Correction
Logarithmic inverse trip time characteristic
Figure 4-11 Trip time characteristics of inverse time ground fault protection with logarithmic inverse charac-
teristic
Logarithmic inverse t =51Ns Tmax – 51Ns TIME DIAL ·51Ns(I/51Ns PICKUP)
Note: For I/51Ns PICKUP > 35 the time applies for I/51Ns PICKUP = 35; for t < 51Ns Tmin the time 51Ns
Tmin applies.
Angle correction for cable converter in two operating points F1/I1 and F2/I2:
Angle correction F1, F2 (for grounded system) 0.0° to 5.0° Increments 0.1°
Current value I1, I2 for the angle correction
for sensitive transformer
for normal 1-A transformer
for normal 5-A transformer
0.001 A to 1.600 A
0.05 A to 35.00 A
0.25 A to 175.00 A
Increments 0.001 A
Increments 0.01 A
Increments 0.05 A
Measurement Tolerance 2 % of setting value or 1 mA
Angle Tolerance 3°
Note: Due to the high sensitivity the linear range of the measuring input I
N
with integrated sensitive input trans-
former is from 0.001A to 1.6 A. For currents greater than 1.6 A, correct directionality can no longer be guar-
anteed.
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