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
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) 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 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) 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
UBase 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), 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-UEN D
Section 8
Voltage protection
Busbar protection REB670
219
Application manual
Summary of Contents for REB670 Series
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