U – Under Frequency Protection - DEMA 400 Series User Manual

81U – Under Frequency Protection
4.3.4.1
The overvoltage protection settings are located Menu> Protection Settings> Frequency
Protection Settings> Under Frequency Protection
Working principle; The measured frequency value is the activation of the protection when the
assigned protection falls below the threshold. The time characteristic is DMT (constant time)
characteristic.
Directional phase overcurrent protection is indicated by f<, f<<, f<<<, f<<<<, f<<<<<,
f<<<<<< in IEC 60617 Standards; PIUF_1, PIUF_2, PIUF_3, PIUF_4, PIUF_5 ve PIUF_6 in
IEC 61850; 81-U-1, 81-U-2, 81-U-3, 81-U-4, 81-U-5 ve 81-U-6 in IEEE/ANSI Standards
EŞİK-1 PIUF_1
EŞİK-2 PIUF_2
EŞİK-3 PIUF_3
EŞİK-4 PIUF_4
EŞİK-5 PIUF_5
EŞİK-6 PIUF_6
The menu view is as follows. The menu consists of five lines.
Under Frequency Protection
IEC 61850
Under Frequency Protection Function Symbols
IEC 60617 IEEE-ANSI
f< 81U-I-1
f<< 81U-I-2
f<<< 81U-I-3
f<<<< 81U-I-4
f<<<<< 81U-I-5
f<<<<<< 81U-I-6
85