ABB RELION RET670 Applications Manual page 569

1MRK 504 163-UUS A
Transformer protection RET670 2.2 ANSI
Application manual
V
ref
3I cos
0
ANSI06000649 V1 EN-US
Figure 280: Characteristic for RCADir equal to -90°
When OpModeSel is set to 3I03V0Cosfi the apparent residual power component in the
direction is measured.
When OpModeSel is set to 3I0 and fi the function will operate if the residual current is
larger than the setting INDirPU and the residual current angle is within the sector
RCADir ± ROADir.
The characteristic for this OpModeSel when RCADir = 0° and ROADir = 80° is shown
in figure 281.
RCA = -90°, ROA = 90°
3I
0
)
) – ang(V
= ang(3I
0 ref
-3V
0
en06000649_ansi.vsd
Section 9
Current protection
563