Siemens SIPROTEC 7SJ61, Manual, Page: 347 / 454

Technical Data
4.13 Ground Fault Protection 50N(s), 51N(s)
SIPROTEC, 7SJ61, Manual
C53000-G1140-C210-1, Release date 02.2008 347
Ground Fault Pickup for All Types of Ground Faults (Inverse Time Characteristic Logarithmic Inverse with Knee
Point)
Influencing Variables
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 current 51Ns 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 2-52
Tolerances
Times inv. 5 %
±
15 ms
def. 1 % of setting value or 10 ms
Power Supply DC Voltage in Range 0.8
≤
V
PS
/V
PSNom
≤
1.15 1 %
Temperature in Range 23.00 °F (–5 °C)
≤ Θ
amb
≤
131.00 °F (55 °C) 0.5 %/10 K
Frequency in range f
Nom
±
5 Hz 1 %
Harmonics
- Up to 10 % 3rd harmonic
- Up to 10 % 5th harmonic
1 %
1 %
Note: When using the sensitive transformer, the linear range of the measuring input for the sensitive ground
fault detection is from 0.001 A to 1.6 A. The function is however still preserved for greater currents.