ABB 615 series Technical Manual page 856

Section 6
Supervision functions
850
Current measurement with two independent three-phase sets of CT cores
Figure 438 and Figure 439
measured with two independent three-phase sets of CT cores.
IL1
IL2
IL3
GUID-8DC3B17A-13FE-4E38-85C6-A228BC03206B-ANSI V3 EN
Figure 438: Connection diagram for current circuit supervision with two sets of three-
phase current transformer protection cores
When using the measurement core for reference current measurement, it
should be noted that the saturation level of the measurement core is much
show diagrams of connections where the reference current is
I_A
I_B
I_C
I_REF
Other protection devices
1MAC059074-MB A
protection relay
CCM
FAIL
I_A
I_B
ALARM
I_C
I_REF
BLOCK
615 series ANSI
Technical Manual