Siemens SIPROTEC 7SA6 Manual page 709

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:
æ
I
------------- -
è
⋅
k I N
τ ⋅
t = ln
------------------------------- -
æ
I
------------- -
è
⋅
k I N
Figure 10-6 Tripping characteristic of the thermal overload protection
7SA6 Manual
C53000-G1176-C156
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
ö
ø
[min]
2
ö
1
–
ø
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
æ ö
I
2
æ ö
I
pre
ç ÷
------------- - – ------------- -
è ø
⋅ ⋅
k I N k I N
è ø
τ ⋅
ln
---------------------------------------------------
2
æ ö
I
1
------------- - –
è ø
⋅
k I N
Technical Data
Parameter:
Setting Value;
Time Factor
τ [min]
1000
500
200
100
50
20
10
6 7 8 10 12
·
I / (k I )
N
[min]
10-41