ABB Relion SMU615 Technical Manual page 145

1MRS758407 B
SMU615
Technical Manual
GUID-C5A6BB27-36F9-4652-A5E4-E3D32CFEA77B V2 EN
Figure 97: Connection diagram for current circuit supervision with two sets of
three-phase current transformer cores (protection and
measurement)
Example of incorrect connection
The currents must be measured with two independent cores, that is, the phase currents
must be measured with a different core than the reference current. A connection
diagram shows an example of a case where the phase currents and the reference
currents are measured from the same core.
Section 5
Supervision functions
139