Hysteresis - DEMA 400 Series User Manual

4.3.3.2.7

Hysteresis

It allows the selection of the minimum and maximum values for the protection to be activated
by entering the value in percentages and the same value being switched off in percentage. For
example, if the undervoltage protection start value is set to 100 V, the hysteresis value is set to
5%, the protection is activated when the protection falls below 95V; If it exceeds 105 V, the
protection is deactivated. This hysteresis value can be selected from 1% to 20%.
4.3.3.2.8 Measurement Mode
The measurement mode can be selected as RMS or Basic Sequence. The basic sequence
measurement is selected to use nominal measured values. The RMS(Root Mean Square)
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.
4.3.3.2.9 Phase Operation Mode
It is the section where the single phase or three phase is chosen fort he system.
47 –Negative Sequence Over Voltage Protection
4.3.3.3
The overvoltage protection settings are Menu> Protection Settings> Voltage Protection
Settings> Negative Sequence Overvoltage Protection
Negative component overvoltage protection; motors are used for protection from overvoltage
due to negative component in the network. It works according to definite time characteristic.
Directional phase overcurrent protection is indicated by U2> in IEC 60617 Standards;
NSI_PIOV_1 in IEC 61850; 67N-I-1, 47-I-1 in IEEE/ANSI Standards
EŞİK-1 NSI_PIOV_1
Negative Sequence Over Voltage Protection Function Symbols
The menu view is as follows. The menu consists of five lines.
Negative Sequence Over Voltage Protection
IEC 61850 IEC 60617
U2>
IEEE-ANSI
47-I-1
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