ABB Relion 650 Series Technical Manual page 273

1MRK 506 326-UUS B
Section 9
9.1 Current circuit supervision CCSRDIF (87)
9.1.1 Identification
Function description
Current circuit supervision
9.1.2 Functionality
Open or short circuited current transformer cores can cause unwanted operation of many
protection functions such as differential, ground-fault current and negative-sequence current
functions.
It must be remembered that a blocking of protection functions at an occurrence of open CT circuit
will mean that the situation will remain and extremely high voltages will stress the secondary
circuit.
Current circuit supervision (CCSRDIF, 87) compares the residual current from a three phase set of
current transformer cores with the neutral point current on a separate input taken from another
set of cores on the current transformer.
A detection of a difference indicates a fault in the circuit and is used as alarm or to block
protection functions expected to give unwanted tripping.
9.1.3 Function block
I3P*
BLOCK
IREF
ANSI08000055 V1 EN-US
Figure 136: CCSRDIF (87) function block
Line distance protection REL650
Technical manual
Secondary system supervision
CCSRDIF (87)
FAIL
ALARM
ANSI08000055-1-en.vsd
© Copyright 2011 ABB Power Grids. All rights reserved
IEC 61850 IEC 60617
identification identification
CCSRDIF -
Secondary system supervision
ANSI/IEEE C37.2
device number
87
Section 9
IP14555-1 v3
M14870-1 v3
M12444-3 v6
M12436-3 v5
267