Rogowski Coils; Figure 21: Connection Of Rogowski Coils - WAGO 750-495/040-00 Series Manual

WAGO-I/O-SYSTEM 750 XTR
750-495/040-00x 3-Phase Power Measurement Module 690 V
7.4.2

Rogowski Coils

The Rogowski coil version is suitable for the connection of Rogowski coils with
secondary voltages up to 88 mV
Like current transformers, Rogowski coils are for electrically isolated
measurement of high currents. They consist of a special coil arrangement that is
removable, so it can be easily wrapped around a conductor or current bar, even
after installation.
The AC current flowing through the conductor induces a magnetic field; in
accordance with the law of induction, this induces a frequency-dependent voltage
in the coil, which is proportional to the current. The primary input current is
calculated from the frequency-dependent voltage, which is proportional to the
current, by configuring the connected Rogowski coil.
The properties of the Rogowski coils used directly affect the measurement
accuracy that can be achieved.
Types RT 500 and RT 2000 can be configured directly. Firmware versions 03
and above also support types RC 70, RC 125 and RC 175. With firmware
versions 05 and above, it is possible to configure freely definable Rogowski coils
by inputting the parameters for mutual inductance and internal resistance.
When connecting Rogowski coils, pay attention to the direction of current, since
otherwise incorrect signs for the power values may be output. See the figure
below:

Figure 21: Connection of Rogowski Coils

In the event of negative power values, verify correct connection of voltage
transformer, current transformer or Rogowski coil
If power measurements erroneously yield negative power values, check whether
you have connected the corresponding voltage transformer, current transformer
or Rogowski coil in the correct orientation.
AC.
RMS
Connect Devices 99
Manual
Version 1.2.0