Time Delayed 2-Step Undercurrent Protection Uc2Ptuc (37) - ABB REL650 Applications Manual

Section 7
Current protection
7.8
7.8.1
7.8.2
224
IEC Normal Inverse
IEC Very Inverse
IEC Inverse
IEC Extremely Inverse
IEC Short Time Inverse
IEC Long Time Inverse
IEC Definite time
ASEA RI
RXIDG (logarithmic)
The different characteristics are described in Technical Manual.
tINNonDir is the definite time delay for the non directional ground-fault current
protection, given in s.
OpVN is set Enabled to activate the trip function of the residual voltage protection.
tVN is the definite time delay for the trip function of the residual voltage protection, given
in s.
Time delayed 2-step undercurrent protection
UC2PTUC (37)
Identification
Function description
Time delayed 2-step undercurrent
protection
Application
Time delayed 2-step undercurrent protection (UC2PTUC ,37) can be used wherever a
"low current" signal is needed. The main application is as a local criterion to increase
security when transfer trip schemes are used. Two different application examples for the
undercurrent protection function are given below. The examples are a power transformer
directly connected to the feeding line and a line connected shunt reactor operating on a
IEC 61850 IEC 60617
identification identification
UC2PTUC
3I<
2
IEC09000131 V2 EN
1MRK 506 334-UUS A
ANSI/IEEE C37.2
device number
37
Application manual