9328900990 Rev L BE1-951 BESTCOMS Software 14-11
Setting Group Selection
Pull down the S
creens 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, has
no folder tabs and is labeled Setting Group Selection - Setting Group Automatic Control Settings.
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 the screen (
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 BE1-951
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.
Figure 14-13. Setting Group Selection Screen
Overcurrent
Pull down the S
creens menu and select Overcurrent Protection or click on the Overcurrent
Protection icon that is shown at the right margin of this paragraph. This screen has five folder
tabs and the first two tabs are 51 tab and the 151 tab.
51 and 151 (Time Overcurrent)
These two tabs (51 and 151) allow you to enter the settings for the time overcurrent elements. BE1-951
relays have four time overcurrent elements.
Figure 14-14 shows the 51 tab; the 151 tab settings are
similar.
Three elements are shown under the 51 tab and one (151N) is shown under the 151 tab. The pull down
Pickup menu allows you to select the relative pickup quantity. BE1-951 relays measure the current input
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