R1FwPPZx
RFFwPPZx
X1FwPPZx
X1RvPPZx
RFFwPPZx
RFRvPPZx
RFFwPPZx
RFRvPPZx
RFRvPPZx
R
(Ohm/phase)
IEC11000418-3-en.vsd
2
2
2
2
2
2
√
1) 1)
Settings RFRvPPZx and RFFwPPZx exist for Zones 3 to 5.
For Zone 1, 2 and RV, setting RFPPZx is applicable for both forward and reverse direction.
1)
IEC11000418 V3 EN-US
Figure 174: ZMFCPDIS Characteristic for the phase-to-phase measuring loops, ohm/phase
domain
Note that for ZMFCPDIS, the reverse zone ZRV, as well as any of zones 3-5, that are
set to
DirMode
=
Reverse
will get their operating impedances inverted (rotated 180
degrees) internally in order to make use of the main settings, which are the
settings designated ‘Fw’. Therefore, a reverse zone will have its Fw-settings
(
RFFwPPZRV
,
X1FwPGZ3
, and so on) applied in the third quadrant, that is, towards
the busbar instead of the line.
The fault loop reach in relation to each fault type may also be presented as in figure 175. The main
intension with this illustration is to make clear how the fault resistive reach should be interpreted.
Note in particular that the setting RFPP always represents the total fault resistance of the loop,
even while the fault resistance (arc) may be divided into parts like for three-phase or phase-to-
phase-to-ground faults. R1Zx and jX1Zx represent the positive sequence impedance from the
measuring point to the fault location.
1MRK 502 066-UUS B Section 7
Impedance protection
347
Technical manual
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