Schweitzer Engineering Laboratories SEL-751 - Table 4.53 Relay Word Bit and Front-Panel Correspondence to Reclosing Relay States

4.139
Date Code 20170927 Instruction Manual SEL-751 Relay
Protection and Logic Functions
Group Settings (SET Command)
The reclosing relay is in one (and only one) of these states (listed in
Table 4.53) at any time. When in a given state, the corresponding Relay Word
bit asserts to logical 1, and the LED illuminates. Automatic reclosing only
takes place when the relay is in the Reclose Cycle State.
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 4.82).
➤ Reclose initiation is unsuccessful because of SELOGIC control
equation setting 79RIS (see Reclose Initiate and Reclose
Initiate Supervision Settings (79RI and 79RIS, Respectively) on
page 4.144).
➤ 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) on
page 4.146].
➤ The close failure timer (setting CFD) times out (see
Figure 4.80).
➤ SELOGIC control equation setting 79DTL = logical 1 (see
Drive-to-Lockout and Drive-to-Last Shot Settings (79DTL and
79DLS, Respectively)).
➤ The Reclose Supervision Limit Timer (setting 79CLSD) times
out (see Figure 4.81 and top of Figure 4.82) and the reclose
enable setting, E79, has setting choices N, 1, 2, 3, 4, C1, C2,
C3, and C4.
➤ A new reclose initiation occurs while the reclosing relay is
timing on an open interval (e.g., flashover in the tank while
breaker is open).
The OPEN command is included in the reclosing relay logic via the factory
SEL
OGIC control equation settings:
79DTL := OC OR … (drive-to-lockout)
Table 4.53 Relay Word Bit and Front-Panel Correspondence to Reclosing
Relay States
Reclosing Relay State
Corresponding
Relay Word Bit
Corresponding
Front-Panel LED
Reset 79RS RECL RESET (Pushbutton LED 1A)
Reclose Cycle 79CY
Lockout 79LO RECL LOCKOUT (Pushbutton LED 1B)