
Date Code 20020215
Close and Reclose Logic
6-17
SEL-351R Instruction Manual
Typically, setting 79RSLD is set less than setting 79RSD. Setting 79RSLD emulates reclosing
relays with motor-driven timers that have a relatively short reset time from the lockout position
to the reset position.
The 79RSD and 79RSLD settings are set independently (setting 79RSLD can even be set
greater than setting 79RSD, if desired). SEL
OGIC
control equation setting 79BRS (block reset
timing) can be set to control reset timing [see
Block Reset Timing Setting (79BRS)
subsection].
Monitoring Open Interval and Reset Timing
Open interval and reset timing can be monitored with the following Relay Word bits:
Relay Word Bits Definition
OPTMN
Indicates that the open interval
timer is actively timing
RSTMN
Indicates that the reset timer is
actively timing
If the open interval timer is actively timing, OPTMN asserts to logical 1. When the SEL-351R
is not timing on an open interval (e.g., it is in the Reset State or in the Lockout State), OPTMN
deasserts to logical 0. The SEL-351R can only time on an open interval when it is in the
Reclose Cycle State, but just because the relay is in the Reclose Cycle State does not necessarily
mean the relay is timing on an open interval. The SEL-351R only times on an open interval
after successful reclose initiation and if no stall conditions are present [see
Open Interval Timing Settings (79SKP and 79STL, respectively)
If the reset timer is actively timing, RSTMN asserts to logical 1. If the reset timer is not timing,
RSTMN deasserts to logical 0. See
Block Reset Timing Setting (79BRS)
subsection.
Reclosing Relay Shot Counter
The shot counter increments for each reclose operation. For example, when the SEL-351R is
timing on open interval 1, 79OI1, it is at shot = 0. When the open interval times out, the shot
counter increments to shot = 1 and so forth for the set open intervals that follow. The shot
counter cannot increment beyond the last shot for automatic reclosing [see
Number of Reclosures (Last Shot)
earlier in this subsection]. The shot counter resets back to
shot = 0 when the reclosing relay returns to the Reset State.
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