Siemens SIMOCODE pro System Manual page 169

Transformation ratio - secondary
Enter the secondary current here, with the "Transformation Ratio - Active"
checkbox activated.
Range: 0 - 15.
Note
In the case of motors with two speeds, the same or different transformation
ratios can be set for each speed, depending upon whether the same or two
different interposing transformers is/are used for each speed.
Application examples
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 up to 3 A): Transformation ratio for
l = 820:1; l
s
Settings (primary and secondary):
• Set current I
• Transformation ratio - primary: 820
• Transformation ratio - secondary: 1
Example 2:
Rated motor current: 225 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 twice
through a current measuring module (0.3 up to 3 A): Transformation ratio for
l = 820 : 2, l
s
Settings (primary and secondary):
• Set current I
• Transformation ratio - primary: 820
• Transformation ratio - secondary: 2.
Example 3:
The motor cable is looped twice through a current measuring module (0.3
up to 3 A, for a motor with a rated current of 0.25 A): Transformation ratio
for I = 1: 2; I
s
Settings (primary and secondary)
• Set current I
• Transformation ratio - primary: 1
• Transformation ratio - secondary: 2
SIMOCODE pro
GWA 4NEB 631 6050-22 DS 03
= 700 A
s
1: 700 A
s
= 225 A
s
1: 225 A
s
= 0.25 A
s
1: 0.25 A
s
Motor protection
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