Basler BE1-CDS220, Instruction Manual

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14-10 BESTCOMS Software BE1-CDS220
Conversions
The Conversions tab (Figure 14-12) brings up the screen that allows entries in per unit. The per unit
conversion for the settings involves entries for the base quantities. When you are entering settings later
on, you can select primary current values, secondary current values, percent, or per unit. If you are using
percent or per unit, then you have to enter the Conversion screen field values regarding three-phase,
phase-to-phase, and phase-to-neutral base quantities. If the settings are entered in terms of primary or
secondary current values, you do not need to enter this information.
Figure 14-12. General Operation Screen, Conversions Tab
Setting Group Selection
Pull down the Screens menu and select Setting Group Selection or click on the Setting Group
Selection icon that is shown at the right margin of this paragraph. This screen (Figure 14-13)
does not have folder tabs and it is labeled Setting Group Selection.
Setting group selection involves programming the relay to automatically select one group out of four
protective element setting groups in response to system conditions. When the system is normal, the
default or normal group is 0. Auxiliary setting groups allow adapting the coordination settings to optimize
them for a predictable situation. Sensitivity and time coordination settings can be adjusted to optimize
sensitivity or clearing time based upon source conditions or to improve security during overload
conditions. Near the bottom of Figure 14-13, there is a Monitor Setting window for Groups 1, 2, and 3.
This field in each group allows you to select which element controls that specific group selection. The
Switch Threshold sets the level for the monitored element and the Switch Time sets the time delay to
prevent the group change from changing the instant that the monitored element exceeds the Switch
Threshold setting. Return Threshold and Time does the same thing for changing back to the previous
group.
You do not have to depend only on monitored conditions to change group selection. The active Setting
Group can be controlled at any point in time by the setting group control logic. (Refer to Section 4,
Protection and Control, for more information on Setting Groups.) The setting group control also has an
alarm output variable SGC (Setting Group Changed). This output is asserted whenever the BE1-CDS220
switches from one setting group to another. The alarm bit is asserted for the SGCON time setting. You
can click in the Setting Group Change (SGC) Alarm Timer (Sec) field and set the SGCON time setting.