Siemens SIPROTEC 7SJ62 Instruction Manual page 447

100
t [min]
50
30
20
10
5
3
2
1
0.5
0.3
0.2
0.1
0.05
1 2
without pre-load:

I
------------- -

⋅
k I N
τ ⋅
ln
t =
------------------------------- -

I
------------- -

⋅
k I N
Willi Anwender
Figure 10-6 Trip Time Characteristic Curves For The Thermal Overload Protection (49)
7SJ62 Manual
C53000-G1140-C121-1
Parameter:
Setting Value
of Time Con-
stant
τ [min]
1000
500
200
100
50
20
10
5
1 2
3 4 5 6 7 8 10 12
·
I/k I
N
2


[min]
2

– 1

100
t [min]
50
30
20
10
5
3
2
1
0.5
0.3
0.2
0.1
1
0.05
1 2
with 90 % pre-load:
2
 
I
------------- -
 
⋅
k I
N
τ ⋅
t ln
= ---------------------------------------------------

I
------------- -

⋅
k I N
Technical Data
Parameter:
Setting Value
of Time Con-
stant
τ [min]
1000
500
200
100
50
20
5
2 10
3 4 5 6 7 8 10 12
·
I/k I
N
2
 I pre 
 
– ------------- -
⋅
 k I 
N
[min]
2

1
–

10-29