BE1-951
Protection and Control
4-7
S G 3
S G 2
S G 1
S G 0
S G C
Load Current
as % of S0-51 <pickup>
4 0
3 0
2 0
1 0
1 0 0
9 0
8 0
7 0
6 0
5 0
1 2 0
1 1 0
1 4 0
1 3 0
1 5 0
S P - G R O U P 1 = 1 0 , 0 , 1 0 , 5 0 , 5 1 P
1 0
1 0
S P - G R O U P 3 = 0 , 0 , 0 , 0 , 0
S P - G R O U P 2 = 0 , 0 , 0 , 0 , 0
0
9 0
8 0
7 0
6 0
5 0
4 0
3 0
2 0
1 0
1 0 0
T I M E
( M I N U T E S )
0
(0.5A)
D2840-22.vsd
01-28-99
Figure 4-4. Automatic Operation Based on Cold-Load Pickup
When the switch to criteria is met for more than one setting group at a time, the function will use the
numerically higher of the enabled settings groups. If the switch to time delay setting is set to 0 for a
setting group, automatic control for that group is disabled. If the return time delay setting is set to 0 for a
setting group, automatic return for that group is disabled and the relay will remain in that settings group
until returned manually of by logic override control.
Group Control by Monitoring Reclose Status
The active setting group may also be controlled by the status of the reclose (79) function. Upon entering
a reclose operation, as the relay steps through an automatic reclose operation, the relay may be instructed
to change to an appropriate setting group using the command SP-GROUP[n] = ,,,,<791, 792, 793 or 794>.
If the monitored element in the SP-GROUP command is 791, 792, 793, or 794, the switch-to time, switch-to
threshold, return time, and return threshold are ignored.
When settings group changes are made via SP-GROUP[n] = ,,,,<791, 792, 793, or 794> the relay will stay
in the last group changed to till the relay returns to reset condition. Upon return to reset condition, the relay
restores setting group 0. The settings group changes via SP-GROUP[n] = ,,,,<791, 792, 793, or 794> can
only raise setting a group number. For instance, one cannot have reclose 1 change to setting group 2 and
then reclose 2 change to setting group 1. When reclose 2 occurs, the relay will remain in setting group 2.
The points in the reclose process that the 791, 792, 793,and 794 setting causes a change to the desired
setting group is when a) the referenced reclose occurs and b) after the breaker closes. For instance, SP-
