when unbalance occurs in the phase currents even if there was nothing
wrong with the measurement circuit.
Reference current measured with core-balanced current transformer
CCM compares the sum of phase currents to the current measured with the core-balanced
CT.
CCM
I_A
I_B
ALARM
FAIL
I_C
I_REF
BLOCK
protection relay
Core 1
(p
ro
tecti
o
n)
IL1
IL2
IL3
I_A
I_B
I_C
I_REF
Co
re
ba
lance
d CT
GUID-DA7A48EF-0F07-4665-9A09-87188E5A9982 V2 EN
Figure 192:
Connection diagram for reference current measurement with core-
balanced current transformer
Current measurement with two independent three-phase sets of CT cores
show diagrams of connections where the reference current is
measured with two independent three-phase sets of CT cores.
Section 6
1MRS240050-IB C
Supervision functions
366
REF615R
Technical Manual
Summary of Contents for RELION REF615R
Page 1: ... RELION PROTECTION AND CONTROL REF615R Technical Manual ...
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