Schweitzer Engineering SEL-351P - Monitoring Open Interval and Reset Timing; Reset Timer

Date Code 990215 Close and Reclose Logic 6-17
SEL-351P Manual Técnico
Reset Timer
The reset timer qualifies circuit breaker closure before taking the relay to the Reset State from
the Reclose Cycle State or the Lockout State. Circuit breaker status is determined by the
SEL
OGIC Control Equation setting 52A. (See Close Logic earlier in this section for more
discussion on SEL
OGIC Control Equation setting 52A. Also see Optoisolated Inputs in
Section 7: Inputs, Outputs, Timers, and Other Control Logic for more discussion on SEL
OGIC
Control Equation setting 52A.)
Setting 79RSD:
Qualifies closures when the SEL-351P is in the Reclose Cycle State. These closures are
usually automatic reclosures resulting from open interval time-out.
It is also the reset time used in sequence coordination schemes [see Sequence Coordination
(79SEQ) discussed later in this subsection].
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 SEL-351P, via the CLOSE
command, or via the SEL
OGIC Control Equation setting CL (see Figure SECTION 6: .1).
Setting 79RSLD is also the reset timer used when the SEL-351P powers up, has individual
settings changed for the active setting group, or the active setting group is changed (see
Reclosing Relay States and Settings/Setting Group Changes earlier in this subsection).
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) later in this
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-351P 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-351P 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-351P only times on an open interval after