DANSK DSF/FPREN 60255-127 PDF

This part of IEC 60255 specifies minimum requirements for over/under voltage relays. The standard includes specification of the protection function, measurement characteristics and time delay characteristics. This part of IEC 60255 specifies defines the influencing factors that affect the accuracy under steady state conditions and performance characteristics during dynamic conditions. The test methodologies for verifying performance characteristics and accuracy are also included in this standard. The over/under voltage functions covered by this standard are the following: IEEE/ANSI C37.2 IEC 61850-7-4 Function Numbers Logical node Phase undervoltage protection 27 PTUV Positive sequence undervoltage protection 27D PTUV Phase overvoltage protection 59 PTOV Neutral/zero-sequence overvoltage protection 59N/59G PTOV Negative sequence/ unbalance overvoltage protection 47 PTOV The general requirements for measuring relays and protection equipment are specified in the standard IEC 60255-1.