ABB RELION 620 Series Technical Manual page 889

1MRS757644 F
620 series
Technical Manual
GUID-C5A6BB27-36F9-4652-A5E4-E3D32CFEA77B V2 EN
Figure 462: 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 6
Supervision functions
883