-3V
0
3I
0
RCA = -90°, ROA = 90°
= ang(3I
0
) – ang(V
ref
)
3I
0
cos
V
ref
en06000649_ansi.vsd
ANSI06000649 V1 EN
Figure 45: RCADir set to -90°
For trip, both the residual current 3I
0
·cos φ and the release voltage 3V
0
, must be larger
than the set levels: INCosPhiPU and VNRelPU.
When the function is activated binary output signals PICKUP and PUDIRIN are activated.
If the output signals are active after the set delay tDef the binary output signals TRIP and
TRDIRIN are activated. The trip from this sub-function has definite time delay.
There is a possibility to increase the operate level for currents where the angle φ is larger
than a set value as shown in figure
46. This is equivalent to blocking of the function if φ >
ROADir. This option is used to handle angle error for the instrument transformers.
1MRK 511 287-UUS A Section 6
Current protection
121
Technical manual
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