ABB RET670 Commissioning Manual page 122

Section 11
Testing functionality by secondary injection
116
4
X +
( 1 XN )
50% of RLdFw
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
1 X [X1+XN]
R 0
2 X 0
R RLdFw
R RFFwPE
3 X 0.85·[X1+XN]
R 0.85·[X1+XN]·1/tan(60°)+RFFwPE
4 X 0.85·[X1+XN]
R -0.85·[X1+XN]·
tan (AngNegRes-90°)
5 X RFFwPE·tan (ArgLd)
R RFFwPE
6 X -0.5·RLdFw·tan (ArgDir)
R 0.5·RLdFw
Table 22 is used together with figure 25.
W
( / loop
)
X
1
85%
5
ArgNegRes
2
7
6
RFFwPE
1MRK 504 165-UEN A
3
60°
W
( / loop
R
IEC09000734-4-en.vsd
Comments
XN=(X -X )/3
0 1
When RLdFW < RFFwPE
When RLdFwPE > RFFwPE
R≈0.491·(X1+XN)+RFFwPE
Can be limited by RFFwPE
Only when RLdFw < RFFwPE
Transformer protection RET670 2.2 IEC
Commissioning manual
)