Siemens siprotec 7SA6 User Manual page 664

Technical Data
100
t [min]
50
30
20
10
5
3
2
1
0.5
0.3
0.2
0.1
0.05
1 2
without Previous Load Current:

I
------------- -

⋅
k I N
τ ⋅
t = ln
------------------------------- -

I
------------- -

⋅
k I N
Figure 10-6 Tripping characteristic of the thermal overload protection
10-36
Parameter:
Setting Value;
Time Factor
τ [min]
1000
500
200
100
50
20
10
5
1 2
3 4 5 6 7 8 10 12
I / (k
2


[min]
2

1
–

100
t [min]
50
30
20
10
5
3
2
1
0.5
0.3
0.2
0.1
0.05
1
·
I )
N
with 90 % Previous Load Current:
t =
5
1 2
2 3 4 5
  2
I
2
 
I
pre
 
------------- - – ------------- -
 
⋅ ⋅
k I N  k I N 
τ ⋅
ln
---------------------------------------------------
2
 
I
------------- - – 1
 
⋅
k I N
C53000-G1176-C133-1
Parameter:
Setting Value;
Time Factor
τ [min]
1000
500
200
100
50
20
10
6 7 8 10 12
·
I / (k I )
N
[min]
7SA6 Manual