6.23
Date Code 20060320 Instruction Manual SEL-311C Relay
Close and Reclose Logic
Reclosing Relay
Figure 6.7 Reclose Blocking for Islanded Generator
If the line is energized, channel VS overvoltage element 59S1 can be set to
assert. Make the following setting:
79STL = 59S1 + . . .
If line voltage is present, Relay Word bit 59S1 asserts, stalling open interval
timing (reclose block). If line voltage is not present, Relay Word bit 59S1
deasserts, allowing open interval timing to proceed (unless some other set
condition stalls open interval timing).
Additional Settings Example 3
Refer to Figure 6.4 and accompanying setting example, showing an
application for setting 79STL.
Other Settings Considerations
If no special skip shot or stall open interval timing conditions are desired,
make the following settings:
79SKP = 0 (numeral 0)
79STL = 0 (numeral 0)
Block Reset Timing
Setting (79BRS)
The block reset timing setting 79BRS keeps the reset timer from timing.
Depending on the reclosing relay state, the reset timer can be loaded with
either reset time:
79RSD (Reset Time from Reclose Cycle)
or
79RSLD (Reset Time from Lockout)
Depending on how setting 79BRS is set, none, one, or both of these reset
times can be controlled. If the reset timer is timing and then 79BRS asserts to:
79BRS = logical 1
reset timing is stopped and does not begin timing again until 79BRS deasserts
to:
79BRS = logical 0
VA,VB,VC
Bus 1
3-phase
1-phase
VS
IA,IB,IC
SEL-311C
52
Generator
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