66
4.3.2.4.12 Measurement Mode
The measurement mode can be selected as RMS or Basic Component. The basic component
measurement is selected to use harmonic-free measured values. The RMS measurement is
selected to use the values calculated by taking the square root of the mean of the squares of
the measured values. This value is also called Active or Effective value.
4.3.2.5 67N – Directional Earth Overcurrent Protection
Directional Earth Overcurrent Protection are located under this sections: Main Menu>
Protection Settings> Current Protection Settings> Directional Earth Overcurrent Protection
Directional earth overcurrent protection is activated when the earth current exceeds the
defined current threshold and the angle between the currents is within the working zone
, I
e
>>, I
e
>>>
through the neutral current transformer. I
e_d
> I
e_d
>>sholds are calculated from the
sum of the phase currents and works according to the neutral current value. In this way, the
device provides directional earth overcurrent protection without connecting a neutral current
transformer.
Directional phase overcurrent protection is indicated by Ie>Ie>>Ie>>>
DEI_PIOC_1, DEI_PIOC_2, DEI_PIOC_3,
DEDI_PIOC_1, DEDI_PIOC_2 in IEC 61850; 67N-I-1, 67N-I-2, 67N-I-3, 67N-DI-1, 67N-
DI-2 in IEEE/ANSI Standards
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