Siemens siprotec 7SA6 User Manual page 648

Technical Data
100
t [s]
30
20
10
7
5
3
2
1
0.7
0.5
0.3
0.2
0.1
0.07
0.05
1 2 3

8.9341

t
INVERSE = ------------------------------------- -

( ⁄
I I
p
100
t [s]
50
20
10
5
3
2
1
0.5
0.3
0.2
0.1
0.05
1 2 3
t
=
LONG INVERSE
Figure 10-2 Trip time characteristics of inverse time overcurrent protection, acc. ANSI/IEEE, (phases and earth)
10-20
D [s]
15
10
5
2
1
0.5
5 10 20
I/I
p

⋅

[s]
0.17966 D
+
2.0938 
)
– 1
D [s]
15
10
5
2
1
0.5
5 10 20
I/I
p
  D
5.6143
⋅
2.18592 [s]
------------------------ - +
 
( ⁄ ) 1
I I
–
p
100
t [s]
30
20
10
7
5
3
2
1
0.7
0.5
0.3
0.2
0.1
0.07
0.5
0.05
1 2 3 5
t
SHORT INVERSE =
100
t [s]
50
20
10
5
3
2
1
0.5
0.3
0.2
0.1
0.05
1 2 3 5
MODERATELY INVERSE
D [s]
15
10
5
2
1
10 20
I/I
p
 
0.2663
⋅
 
0.03393 D
------------------------------------- - +
 1.2969 
( ⁄ )
I I – 1
p
D [s]
15
10
5
2
1
0.5
10 20
I/I
p
 
0.0103
⋅
 
t 0.0228 D
= -------------------------------- - +
 0.02 
( ⁄ )
I I 1
–
p
7SA6 Manual
C53000-G1176-C133-1
[s]
[s]