ABB RELION REB670, Applications Manual

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For other applications it has to be decided case by case.
tAlarm : The time delay for alarm is set by this parameter. Normally, few seconds delay
can be used on capacitor banks alarm. For fuse failure supervision (SDDRFUF) the
alarm delay can be set to zero.
8.5 Loss of voltage check LOVPTUV (27)
SEMOD171868-1 v2
8.5.1 Identification
SEMOD171954-2 v2
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Loss of voltage check LOVPTUV - 27
8.5.2 Application
SEMOD171876-4 v3
The trip of the circuit breaker at a prolonged loss of voltage at all the three phases is
normally used in automatic restoration systems to facilitate the system restoration after
a major blackout. Loss of voltage check (LOVPTUV, 27) generates a TRIP signal only
if the voltage in all the three phases is low for more than the set time. If the trip to the
circuit breaker is not required, LOVPTUV (27) is used for signallization only through
an output contact or through the event recording function.
8.5.3 Setting guidelines
SEMOD171929-4 v5
Loss of voltage check (LOVPTUV, 27) is in principle independent of the protection
functions. It requires to be set to open the circuit breaker in order to allow a simple
system restoration following a main voltage loss of a big part of the network and only
when the voltage is lost with breakers still closed.
All settings are in primary values or per unit. Set operate level per phase to typically
70% of the global parameter
VBase level. Set the time delay tTrip =5-20 seconds.
8.5.3.1 Advanced users settings
SEMOD171929-8 v4
For advanced users the following parameters need also to be set. Set the length of the
trip pulse to typical
tPulse =0.15 sec. Set the blocking time tBlock to block Loss of
voltage check (LOVPTUV, 27), if some but not all voltage are low, to typical 5.0
seconds and set the time delay for enabling the function after restoration
tRestore to 3 -
40 seconds.
1MRK 505 370-UUS A
Section 8
Voltage protection
Busbar protection REB670 2.2 ANSI 259
Application manual