Measuring Current With An External Current Transformer (Interposing Transformer) - Siemens SIMOCODE pro C System Manual

12.2.5

Measuring current with an external current transformer (interposing transformer)

Functional principle
SIMOCODE pro can be operated with external current transformers. The secondary cables
of the current transformer are looped through the three feed-through openings of the current
measuring module, and short-circuited. The secondary current of the external current
transformer is the primary current of the SIMOCODE pro current measuring module.
Note
If the main circuit is using rated current, the secondary current of the current transformer
must be within the setting range of the current measuring module used!
Figure 12-29 Measuring current with an external 3UF18 current transformer
Transformation ratio
The transformation ratio is calculated using the following formula:
In the following examples, the displayed actual current flowing does not need to be
converted, even when an interposing transformer is used, since SIMOCODE pro only
outputs the proportional value, based upon the parameterized current setting I
SIMOCODE pro
System Manual, 05/2019, A5E40507475002A/RS-AD/004
Mounting, wiring, connecting, system interfaces, configuration guidelines
12.2 Wiring, connecting
.
s
233