ABB RELION REX640 Technical Manual page 1218

Section 6
Supervision functions
1212
GUID-5F519CE4-1DD8-47F8-B76A-103D6862CBF6 V1 EN
Figure 660: 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.
1MRS759142 C
REX640
Technical Manual