Siemens siprotec 7SA6 - Page 694

Technical Data
10-26 7SA6 Manual
C53000-G1176-C156
Logarithmic inverse:
Note: For currents I/3I0P ≥ 35 the tripping time is constant.
Figure 10-4 Trip time characteristics of inverse time overcurrent protection with logarithmic
inverse characteristic
Figure 10-5 Trip time characteristics of the zero sequence voltage protection U
0inv.
1 2 3 4 5 6 7 10 20 30 40
0
2
4
6
8
I/3I0P
t/s
T 3I0Pmax
T 3I0Pmin
3I0P–FACTOR
T 3I0P
1.00
1.351.70
8
tT
3I0Pmax
T
3I0P
ln(I/3I0P)⋅–=
0 20 40 60 80 100 120 140
0.1
0.2
0.3
0.4
0.5
0.7
1
2
3
4
5
10
t/s
3U
0
/V
1V 2V 3V 4V 5V
U
0
inverse: with U
0min
= parameter U0inv. minimum (Adr. 3183)
t
2s
0,25 U
0
V⁄ U
0min
V⁄–
-------------------------------------------------------------=
Parameter:
U0inv. mini-
mum