Siemens SIMOCODE pro - Application Example

Parameters
4.1 Motor protection
SIMOCODE pro - Parameterize
Operating Manual, 04/2017, A5E40507630002A/RS-AA/001
37
4.1.2.4
Application example
Example 1:
Rated motor current: 700 A.
A 3UF18 68-3G current transformer (205 to 820 A) is used as interposing transformer
(transformation ratio 820 : 1), the secondary side is looped once through a current
measuring module (0.3 A to 3 A):
Transformation ratio for I
s
= 820 : 1; I
s
= 700 A
Settings (primary and secondary)
● Set current I
s
1: 700 A
● I
s
1 Transformation ratio primary: 820
● I
s
1 Transformation ratio secondary: 1
Example 2:
Rated motor current: 225 A.
A 3UF1868-3G current transformer (205 to 820 A) is used as interposing transformer
(transformation ratio 820 : 1), the secondary side is looped twice through a current
measuring module (0.3 A to 3 A):
Transformation ratio for I
s
= 820 : 2; I
s
= 225 A
Settings (primary and secondary)
● Set current I
s
1: 225 A
● I
s
1 Transformation ratio primary: 820
● I
s
1 Transformation ratio secondary: 2
Example 3:
The motor cable is looped twice through a current measuring module (0.3 to 3 A, for a motor
with a rated current of 0.25 A):
Transformation ratio for I
s
= 1 : 2; I
s
= 0.25 A
Settings (primary and secondary)
● Set current I
s
1: 0.25 A
● I
s
1 Transformation ratio primary: 1
● I
s
1 Transformation ratio secondary: 2