For trip, both the residual current 3I
0
·cos φ and the release voltage 3U
0
, must be larger
than the set levels: INCosPhi> and UNRel>.
When the function is activated binary output signals START and STDIRIN 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
102. This is equivalent to blocking of the
function if φ > ROADir. This option is used to handle angle error for the instrument
transformers.
Operate area
ROADir
IEC06000650_2_en.vsd
IEC06000650 V2 EN
Figure 102: Characteristic with ROADir restriction
The function indicates forward/reverse direction to the fault. Reverse direction is
defined as 3I
0
·cos (φ + 180°) ≥ the set value.
It is also possible to tilt the characteristic to compensate for current transformer angle
error with a setting RCAComp as shown in the figure
103:
Section 8 1MRK 502 048-UEN A
Current protection
208
Technical manual
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