Manual MRM3-2 GB
Woodward
TD_MRM3-2_09.08_GB_Rev.New
53
7.4 Tripping
characteristics
7.4.1 Tripping characteristic for max. starting time
The formula for calculating the tripping characteristic is:
Inverse Time Characteristic
_
·
this applies if I/I_Start > = 0,707
t
aus
= 2 x ts
this applies if I/I_Start< 0,707
With:
t
aus
= tripping time
ts = starting time at rated starting current (rated voltage) or rated starting time
I
=
effective
current
I_start = setting value of rated starting current
Figure 7.1: Tripping characteristic for max. starting time
0,01
0,10
1,00
10,00
100,00
1000,00
0,01
0,10
1,00
10,00
[s]
500
400
ts =
200
100
80
40
20
10
1
[I_Start]
⎥
⎦
⎤
⎢
⎣
⎡
start
_
I
I
