Reset Delay - DEMA 400 Series User Manual

Reset type and time indicates that, the protection function which starts counting with a current
above the specified current threshold, shows the curve and value that determines the duration
of the failure if the current falls below the threshold without tripping.
The reset type can be selected as DMT (fixed time) and IDMT (reverse constant time)
according to the selected protection curve type. The reset types used by various protection
curves and their parameters are examined in Menu> Protection Settings> Protection and Reset
Curves.
4.3.2.7.7

Reset Delay

According to the menu settings, exceeding 5.00 In and without breaker tripping, It was
selected to count the DMT (constant time) reset time (0.04 s) after the current has dropped
below 5.00 In. 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).
4.3.2.7.8 RTMS
Reset Curves are the 'Reset Time Multiplier' used in the Universal Formula. The Reset Type
is activated when it is selected as IDMT. The setting range of the multiplier can be selected in
the range (0,025 – 5).
4.3.3 Voltage Protection Settings
Voltage Protection Settings can be selected from Main Menu> Protection Settings> Voltage
Protection Settings
Relay protection of the line / motor voltage protection briefly; It operates according to the
principle of deactivating the protected part by comparing the voltage information to the relay
with the voltage information assigned in the protection functions.
The function symbols on the device setting screen are shown according to IEC 61850, IEC
60617 and IEEE ANSI standards. The function symbol selection according to these standards
is as follows: Main Menu> System Settings> Function Symbol
• ANSI 59 – Over Voltage Protection
• ANSI 27 – Under Voltage Protection
• ANSI 47 - Negative Sequence Overvoltage Protection
• ANSI 59N - Neutral Overvoltage Protection
Voltage protection settings menu device screen is as follows.
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