ABB REB670 Series, Applications Manual

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Section 8 Voltage protection
8.1 Two step undervoltage protection UV2PTUV
IP14544-1 v3
8.1.1 Identification
M16876-1 v7
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Two step undervoltage protection UV2PTUV
3U<
SYMBOL-R-2U-GREATER-THAN V2 EN-US
27
8.1.2 Setting guidelines
M13851-3 v9
All the voltage conditions in the system where UV2PTUV performs its functions should be
considered. The same also applies to the associated equipment, its voltage and time
characteristic.
There is a very wide application area where general undervoltage functions are used. All
voltage-related settings are made as a percentage of the global base value
UBase, which
normally is set to the primary rated voltage level (phase-to-phase) of the power system or the
high voltage equipment under consideration.
The trip time setting for UV2PTUV is normally not critical, since there must be enough time
available for the main protection to clear short circuits and earth faults.
Some applications and related setting guidelines for the voltage level are described in the
following sections.
8.1.2.1 Equipment protection, such as for motors and generators
M13851-50 v3
The setting must be below the lowest occurring "normal" voltage and above the lowest
acceptable voltage for the equipment.
8.1.2.2 Disconnected equipment detection
M13851-53 v3
The setting must be below the lowest occurring "normal" voltage and above the highest
occurring voltage, caused by inductive or capacitive coupling, when the equipment is
disconnected.
8.1.2.3 Power supply quality
M13851-56 v3
The setting must be below the lowest occurring "normal" voltage and above the lowest
acceptable voltage, due to regulation, good practice or other agreements.
1MRK 505 370-UEN D Section 8
Voltage protection
Busbar protection REB670 207
Application manual