ABB RED670 - Page 125

R
X
RFFwPE
1
3
5
2
4
ArgNegRes
85%
50% of RLdFw
6
IEC09000734-4-en.vsd
7
60°
)
/( loopW
)
/( loopW
)1( XNX +
IEC09000734 V4 EN-US
Figure 25: Operating characteristic for phase selection function, forward
direction single-phase faults
Table 22: Test points for phase-to-earth loop L3-E (Ohm/loop)
Test point Reach Value Comments
1 X [X1+XN] XN=(X
0
-X
1
)/3
R 0
2 X 0
R RLdFw When RLdFW < RFFwPE
R RFFwPE When RLdFwPE > RFFwPE
3 X 0.85·[X1+XN] R≈0.491·(X1+XN)+RFFwPE
R 0.85·[X1+XN]·1/tan(60°)+RFFwPE
4 X 0.85·[X1+XN] Can be limited by RFFwPE
R -0.85·[X1+XN]·
tan (AngNegRes-90°)
5 X RFFwPE·tan (ArgLd) Only when RLdFw < RFFwPE
R RFFwPE
6 X -0.5·RLdFw·tan (ArgDir)
R 0.5·RLdFw
Table 22 is used together with figure 25.
1MRK 505 378-UEN A Section 11
Testing functionality by secondary injection
Line differential protection RED670 2.2 IEC 119
Commissioning manual