Schweitzer Engineering SEL-351P, Quick Start Manual

Page: 307 / 674

Date Code 990215 Close and Reclose Logic 6-13
SEL-351P Manual Técnico
Lockout State
The reclosing relay goes to the Lockout State if any one of the following occurs:
•
The shot counter is equal to or greater than the last shot at time of reclose initiation
(e.g., all automatic reclosing attempts are unsuccessful – see Figure SECTION 6: .6).
•
Reclose initiation is unsuccessful because of SEL
OGIC
Control Equation setting 79RIS
[see Reclose Initiate and Reclose Initiate Supervision Settings (79RI and 79RIS,
respectively) later in this subsection].
•
The circuit breaker opens without reclose initiation (e.g., an external trip).
•
The shot counter is equal to or greater than last shot, and the circuit breaker is open
(e.g., the shot counter is driven to last shot with SEL
OGIC
Control Equation setting
79DLS while open interval timing is in progress). See Drive-to-Lockout and Drive-to-
Last Shot Settings (79DTL and 79DLS, respectively) later in this subsection.
•
The close failure timer (setting CFD) times out (see Figure SECTION 6: .1).
•
SEL
OGIC
Control Equation setting 79DTL = logical 1 [see Drive-to-Lockout and Drive-
to-Last Shot Settings (79DTL and 79DLS, respectively) later in this subsection].
•
The Reclose Supervision Limit Timer (setting 79CLSD) times out (see
Figure SECTION 6: .2 and top of Figure SECTION 6: .3).
Reclosing Relay States and Settings/Setting Group Changes
If individual settings are changed for the active setting group or the active setting group is
changed, all of the following occur:
•
The reclosing relay remains in the state it was in before the settings change.
•
The shot counter is driven to last shot (last shot corresponding to the new settings; see
discussion on last shot that follows).
•
The reset timer is loaded with reset time setting 79RSLD (see discussion on reset timing
later in this section).
If the relay happened to be in the Reclose Cycle State and was timing on an open interval before
the settings change, the relay would be in the Reclose Cycle State after the settings change, but
the relay would immediately go to the Lockout State. This is because the breaker is open and the
relay is at last shot after the settings change, so no more automatic reclosures are available.
If the circuit breaker remains closed through the settings change, the reset timer times out on
reset time setting 79RSLD after the settings change and goes to the Reset State (if it is not
already in the Reset State), and the shot counter returns to shot = 0. If the relay happens to trip
during this reset timing, the SEL-351P will immediately go to the Lockout State, because shot =
last shot.