Reset Delay - DEMA 400 Series User Manual

curves and their parameters are examined in Main Menu> Protection Settings> Protection and
Reset Curves.
4.3.2.1.7

Reset Delay

According to the menu settings, It was selected to count the DMT (constant time) reset time
(0.04 s) after the current has dropped below 5.00 In without exceeding 5.00 In and without
breaker tripping. Thus, after the current falls below the threshold, 40 ms will be counted. If
the threshold is not exceeded until the end of this period, the protection function trip time
counter will be reseted. Reset delay thresholds are in the range of (0-60).
4.3.2.1.8 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.
The current values which are protected according to the measured mode change according to
the mode. The measurement mode can be set separately for each threshold.
4.3.2.2 Earth Overcurrent Protection
Earth overcurrent protection settings are located under this sections: Main Menu> Protection
Settings> Current Protection Settings> Earth Overcurrent Protection.
Earth-overcurrent protection is activated as soon as the current exceeds the threshold current
respect to earth current.
through the neutral current transformer. Ie_d> Ie_d >> thresholds are based on the neutral
current value obtained by calculating the sum of the phase currents. In this way, it is ensured
that the device performs over-current protection without connecting the neutral current
transformer.
Earth Overcurrent Protections are indicated by I
EI_PIOC_1, EI_PIOC_2, EI_PIOC_3, EDI_PIOC_1 ve EDI_PIOC_2 in IEC 61850;
50/51N-I-1, 50/51N-I-2, 50/51N-I-3, 50/51N-DI-1 ve 50/51N-DI-2 in IEEE/ANSI Standards.
For example, the sign Ie >> indicates that the protection is monitored by the earth current and
the second phase is working at the overcurrent threshold.
The Ie> Ie >> Ie >>> thresholds operate according to the current flow
>, I >>, I >>>, I
e e e e_d
56
> I >> in IEC 60617;
e_d