This setting opens an opportunity to enable phase-to-earth measurement for phase-to-
phase-earth faults. It determines the level of residual current (3I0) above which phase-
to-earth measurement is activated (and phase-to-phase measurement is blocked). The
relations are defined with the equation.
0 max
Re
3
100
ph
IN leasePE
I I× ³ ×
EQUATION2548 V1 EN (Equation 80)
Where:
INReleasePE
the setting for the minimum residual current needed to enable operation in the phase-
to-earth fault loops in %
I
phmax
the maximum phase current in any of the three phases
By default, this setting is set excessively high to always enable phase-to-phase
measurement for phase-to-phase-earth faults. This default setting value must be
maintained unless there are very specific reasons to enable phase-to-earth
measurement. Even with the default setting value, phase-to-earth measurement is
activated whenever appropriate, like in the case of simultaneous faults: two earth
faults at the same time, one each on the two circuits of a double line.
One specific situation where the INReleasePE setting should be altered is for cross-
country faults in high impedance earthed networks, in order to make sure that
operation is phase-to-earth. This is particularly important when using phase
preference logic, since it is only working per phase, not for phase-to-phase
measurement. The limit should be set so that it will be exceeded during a cross-
country fault.
8.3 High speed distance protection for series
compensated lines ZMFCPDIS
ZMFCPDIS can be used according to the application description
below only if VT and CT of the line feeder are wired to REG670.
8.3.1 Identification
Function description
IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
High speed distance protection zone
(zone 1-6)
ZMFCPDIS
S00346 V1 EN
21
1MRK 502 071-UEN - Section 8
Impedance protection
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062 213
Application manual
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