ABB Relion 670 series, Technical Reference Manual

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• Logical 1 on functional input BLOCK inhibits the output PICKUP signal
instantaneously.
• The INHIBIT internal signal is activated, if the power swing has been detected and
the measured impedance remains within its operate characteristic for the time,
which is longer than the time delay set on
tR2 timer. It is possible to disable this
condition by connecting the logical 1 signal to the BLK_SS functional input.
• The INHIBIT internal signal is activated after the time delay, set on tR1 timer, if
an ground-fault appears during the power swing (input IOCHECK is high) and the
power swing has been detected before the ground-fault (activation of the signal
I0CHECK). It is possible to disable this condition by connecting the logical 1
signal to the BLK_I0 functional input.
• The INHIBIT logical signals becomes logical 1, if the functional input I0CHECK
appears within the time delay, set on
tGF timer and the impedance has been seen
within the outer characteristic of ZMRPSB (68) operate characteristic in all three
phases. This function prevents the operation of ZMRPSB (68) function in cases,
when the circuit breaker closes onto persistent single-pole fault after single-pole
autoreclosing dead time, if the initial single-pole fault and single-pole opening of
the circuit breaker causes the power swing in the remaining two phases.
6.11.3 Function block
ANSI06000264-2-en.vsd
ZMRPSB (68)
I3P*
V3P*
BLOCK
BLK_SS
BLK_I0
BLK1PH
REL1PH
BLK2PH
REL2PH
I0CHECK
TRSP
EXT_PSD PICKUP
ZOUT
ZIN
ANSI06000264 V2 EN
Figure 188: ZMRPSB (68) function block
1MRK505222-UUS C
Section 6
Impedance protection
353
Technical reference manual