ABB REB670 - Equipment Protection, Capacitors; Equipment Protection, such as for Motors, Generators, Reactors and Transformers; High Impedance Grounded Systems; Power Supply Quality

8.2.3.1 Equipment protection, such as for motors, generators, reactors and
transformers
M13852-10 v3
High voltage will cause overexcitation of the core and deteriorate the winding
insulation. The setting has to be well above the highest occurring "normal" voltage and
well below the highest acceptable voltage for the equipment.
8.2.3.2
Equipment protection, capacitors
M13852-13 v1
High voltage will deteriorate the dielectricum and the insulation. The setting has to be
well above the highest occurring "normal" voltage and well below the highest
acceptable voltage for the capacitor
.
8.2.3.3 Power supply quality
M13852-16 v1
The setting has to be well above the highest occurring "normal" voltage and below the
highest acceptable voltage, due to regulation, good practice or other agreements.
8.2.3.4 High impedance grounded systems
M13852-19 v6
In high impedance grounded systems, ground-faults cause a voltage increase in the
non-faulty phases. Two step overvoltage protection (OV2PTOV, 59) is used to detect
such faults. The setting must be above the highest occurring "normal" voltage and
below the lowest occurring voltage during faults. A metallic single-phase ground-fault
causes the non-faulted phase voltages to increase a factor of √3.
8.2.3.5 The following settings can be done for the two step overvoltage
protection
M13852-22 v10
ConnType: Sets whether the measurement shall be phase-to-ground fundamental value,
phase-to-phase fundamental value, phase-to-ground RMS value or phase-to-phase
RMS value.
Operation: Disabled/Enabled.
VBase (given in GlobalBaseSel): Base voltage phase to phase in primary kV. This
voltage is used as reference for voltage setting. OV2PTOV (59) measures selectively
phase-to-ground voltages, or phase-to-phase voltage chosen by the setting ConnType.
The function will operate if the voltage gets lower than the set percentage of VBase.
When ConnType is set to PhN DFT or PhN RMS then the IED automatically divides set
value for VBase by √3. When ConnType is set to PhPh DFT or PhPh RMS then set
value for VBase is used. Therefore, always set VBase as rated primary phase-to-phase
ground voltage of the protected object. If phase to neutral (PhN) measurement is
Section 8 1MRK 505 370-UUS A
Voltage protection
248 Busbar protection REB670 2.2 ANSI
Application manual