Siemens SIPROTEC 4 7SJ61 - Page 318

Ground Fault Pickup for All Types of Ground Faults (Inverse Time Characteristic Logarithmic inverse)
Pickup Current 50Ns
For sensitive transformer
For normal 1-A transformer
For normal 5-A transformer
0.001 A to 1.400 A
0.05 A to 4.00 A
0.25 A to 20.00 A
Increments
0.001 A
Increments
0.01 A
Increments
0.05 A
Starting current factor 51Ns Startpoint 1.0 to 4.0 Increments 0.1
Time factor 51Ns TIME DIAL 0.05 s to 15.00 s; ∞ Increments
0.01 s
Maximum time 51Ns Tmax 0.00 s to 30.00 s Increments
0.01 s
Minimum time 51Ns Tmin 0.00 s to 30.00 s Increments
0.01 s
Characteristics see Figure 2-53
Tolerances
Times
inv.
5 % ± 15 ms for 2 ≤ Ι/Ι
51Ns
≤ 20 and 51Ns TIME DIAL ≥ 1 s
def. 1 % of setting value or 10 ms
Ground Fault Pickup for All Types of Ground Faults (Inverse Time Characteristic Logarithmic Inverse with Knee
Point)
Pickup Current 50Ns
for sensitive transformer
for normal 1-A transformer
for normal 5-A transformer
0.003 A to 0.500 A
0.05 A to 4.00 A
0.25 A to 20.00 A
Increments
0.001 A
Increments
0.01 A
Increments
0.05 A
Minimum time 51Ns T min 0.10 s to 30.00 s Increments 0.01
s
Pickup current51Ns I T min
for sensitive transformer
for normal 1-A transformer
for normal 5-A transformer
0.003 A to 1.400 A
0.05 A to 20.00 A
0.25 A to 100.00 A
Increments
0.001 A
Increments 0.01
A
Increments 0.05
A
Knee-point time 51Ns T knee 0.20 s to 100.00 s Increments
0.01 s
Pickup current 51Ns I T knee
for sensitive transformer
for normal 1-A transformer
for normal 5-A transformer
0.003 A to 0.650 A
0.05 A to 17.00 A
0.25 A to 85.00 A
Increments
0.001 A
Increments 0.01
A
Increments 0.05
A
Maximum time 51Ns T max 0.00 s to 30.00 s Increments
0.01 s
Time factor 51Ns TD 0.05 s to 1.50 s Increments
0.01 s
Characteristics see Figure 2-54
Technical Data
4.13 Ground Fault Detection (Sensitive/Insensitive)
318 SIPROTEC 4, 7SJ61, Manual
C53000-G1140-C210-6, Edition 05.2016