Basler Electric DGC-2020ES - Manual (Page 64)

56 9469200990 Rev C
The Undervoltage screen is found in the BESTCOMSPlus Settings Explorer under the Generator
Protection, Voltage category. If using the front panel, navigate to Settings > Generator Protection > 27
Undervoltage. The BESTCOMSPlus Undervoltage screen is illustrated in Figure 21.
Figure 21. Settings Explorer, Generator Protection, Voltage, Undervoltage (27) Screen
Overvoltage (59)
Two sets of overvoltage settings are provided for this element: one for three-phase generator connections
and one for single-phase generator connections. The pickup setting entered is based on the PT
secondary side (DGC-2020ES). When a single-phase override contact input is received, the DGC-
2020ES automatically switches from the three-phase overvoltage settings to the single-phase overvoltage
settings.
An overvoltage condition is annunciated when the average of the three-phase (three-phase mode) or the
line-to-line voltage (single-phase mode) increases above the corresponding 59 pickup setting for the
duration of the corresponding 59 activation delay. An overvoltage annunciation can be user-selected to
trigger a pre-alarm (warning) or alarm (shutdown). An overvoltage annunciation can also be user-
configured to close a programmable output.
The hysteresis setting functions as an undervoltage dropout by preventing rapid switching of the pickup
output.
A low-line scale factor setting is used to automatically adjust the overvoltage pickup settings in
applications that may utilize more than one type of genset connection. The scale factor setting is
implemented when the DGC-2020ES senses a contact closure at a contact input programmed to activate
low-line override. This triggers scaling of the protection settings. The value of the scale factor setting
serves as a multiplier for the pickup settings. For example, if a scale factor contact input is received by the
DGC-2020ES and the scale factor setting is 2.000, the pickup setting will be doubled (2.000
× PU).
The element is disabled when Alarm Configuration is set to “None”. Element status is available in
BESTlogicPlus Programmable Logic when “Status Only” is selected.
Settings which are related to machine ratings can be set in either actual units of voltage or in per unit
values. When a native unit is edited, BESTCOMSPlus automatically recalculates the per unit value based
on the native unit setting and the rated data parameter (on the System Parameters, Rated Data screen)
associated with it. When a per unit value is edited, BESTCOMSPlus automatically recalculates the native
value based on the per unit setting and the rated data parameter associated with it.
Once all per unit values are assigned, if the rated data parameters are changed, BESTCOMSPlus
automatically recalculates all native unit settings based on the modified rated data parameters.
The following settings have native units of Secondary Volts, and the rated data associated with them is
Rated Secondary Volts (on the System Parameters, Rated Data screen).
Generator Protection DGC-2020ES