Siemens siprotec 7SA6 - Page 693

Technical Data
10-257SA6 Manual
C53000-G1176-C156
Figure 10-3 Trip time characteristics of inverse time overcurrent protection, acc. ANSI/IEEE (phases and earth)
DEFINITE INVERSE
D[s]
I / I
p
1
2
5
10
15
0.5
1
0.3
0.1
1 2 3 5 10 20
100
20
10
5
2
0.5
0.2
0.05
VERY INVERSE
EXTREMELY INVERSE
D[s]
t[s]
t[s]
I / I
p
I / I
p
1
2
5
10
15
0.5
D[s]
1
2
5
10
15
0.5
1
0.3
0.1
1235
10
20
100
20
10
5
2
0.5
0.2
0.05
[s]
1 2 3 5 10 20
0.3
0.1
100
20
10
2
0.05
5
[s]
0.2
0.5
1
t[s]
3
t
3,922
II
p
⁄()
2
1–
--------------------------- 0.0982+
èø
ç÷
æö
D⋅=
t
5.64
II
p
⁄()
2
1–
--------------------------- 0.02434+
èø
ç÷
æö
D⋅=
t
0.4797
II
p
⁄()
1.5625
1–
-------------------------------------- 0.21359+
èø
ç÷
æö
D⋅=
30
3
3
[s]
30
30
tTriptime
D Setting value time multiplier
I Fault current
I
p
Setting value current
Note: For earth fault read 3I
0p
in-
stead of
I
p
and D
3I0p
instead of D
Ip