Phase-To-Ground Fault - ABB REL650 series Technical Manual

Section 6
Impedance protection
6.2.6.1
132

Phase-to-ground fault

Index PHS in images and equations reference settings for Phase selection
with load encroachment function FDPSPDIS (21).
VA B C ( , )
=
Z
n
PHS
IA B C ( , )
EQUATION1554 V1 EN
where:
n corresponds to the particular phase (n=1, 2 or 3)
The characteristic for FDPSPDIS (21) function at phase-to-ground fault is according to
figure 53. The characteristic has a fixed angle for the resistive boundary in the first
quadrant of 60°.
The resistance RN and reactance XN are the impedance in the ground-return path defined
according to equation 26
-
R 0 R 1
=
RN
3
EQUATION1256 V1 EN
-
X 0 X 1
=
XN
3
EQUATION1257 V1 EN
and equation 27.
1MRK 506 335-UUS A
(Equation 25)
(Equation 26)
(Equation 27)
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