6.16
SEL-311C Relay Instruction Manual Date Code 20060320
Close and Reclose Logic
Reclosing Relay
Setting 79RSLD
Qualifies closures when the relay is in the Lockout State. These closures are
usually manual closures. These manual closures can originate external to the
relay, via the CLOSE command, or via the SEL
OGIC control equation setting
CL (see Figure 6.1).
Setting 79RSLD is also the reset timer used when the relay powers up, has
individual settings changed for the active setting group, or the active setting
group is changed (see Reclosing Relay States After a Settings or Setting Group
Change on page 6.13).
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) on page 6.23).
Monitoring Open Interval and Reset Timing
Open interval and reset timing can be monitored with the Relay Word bits
listed in Table 6.3.
If the open interval timer is actively timing, OPTMN asserts to logical 1.
When the relay 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 relay 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 relay only times on an open interval after
successful reclose initiation and if no stall conditions are present (see Skip
Shot and Stall Open Interval Timing Settings (79SKP and 79STL,
Respectively) on page 6.21).
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).
Reclosing Relay
Shot Counter
Refer to Figure 6.6.
The shot counter increments for each reclose operation. For example, when
the relay 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 Determination of Number of Reclosures
(Last Shot) on page 6.15). The shot counter resets back to shot = 0 when the
reclosing relay returns to the Reset State.
Table 6.3 Relay Word Bits Used to Monitor Open Interval and Reset Timing
Relay Word
Bits
Definition
OPTMN Indicates that the open interval timer is actively timing
RSTMN Indicates that the reset timer is actively timing
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