Siemens siprotec 7SA6, Manual

Page: 709 / 876

Technical Data
10-41
7SA6 Manual
C53000-G1176-C156
Figure 10-6 Tripping characteristic of the thermal overload protection
1
0.3
0.1
1 2 3 5 10 12
100
20
10
5
2
0.5
0.2
0.05
t [min] t [min]
I / (k
·
I
N
)
1000
1
0.3
0.1
100
20
10
5
2
0.5
0.2
0.05
[min]
3
30 30
3
Parameter:
Setting Value;
Time Factor
20
200
500
100
50
10
5
2
1
4 6 7 8
50
t
τ
I
k I
N
⋅
--------------
è ø
æ ö
2
I
k I
N
⋅
--------------
è ø
æ ö
2
1
–
--------------------------------
ln
⋅
=
without Previous Load Current:
I / (k
·
I
N
)
1 2 3 5 10 12 4 6 7 8
with 90 % Previous Load Current:
t
τ
I
k I
N
⋅
--------------
è ø
æ ö
2
I
p re
k I
N
⋅
--------------
è ø
ç ÷
æ ö
2
–
I
k
I
N
⋅
--------------
è ø
æ ö
2
1 –
---------------------------------------------------
ln
⋅
=
50
Parameter:
Setting Value;
Time Factor
1000
500
200
100
50
20
10
5
2 1
τ
[min]
τ
[min]
[min]