ABB REO 517 Applications Manual page 68

58
3 zone impedance protection (Z(n)RW)
RFPP
2
Reverse
Non-
directional
zone
)LJXUH  'LIIHUHQW FKDUDFWHULVWLFV IRU LPSHGDQFH PHDVXULQJ ]RQHV IRU SKDVHWR
SKDVH PHDVXUHPHQWV
The zero sequence compensation factor (K
direction independent of fault type and hence gives selectivity for both phase-to-phase
and earth faults in two phase solidly earthed systems. Different setting values are pos-
sible on the resistive reach for phase to earth faults (RFPE) and for phase-to-phase faults
(RFPP) in the protection function.
jX
X
3
X
1
Forward
zone
zone
X
2
) is used to get correct reach in the reactive
N
/LQH LPSHGDQFH
Z
L
RFPP RFPP
1
3
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&KDSWHU 
R