6.11
Date Code 20060320 Instruction Manual SEL-311C Relay
Close and Reclose Logic
Reclosing Relay
Reclosing Relay
Note that input:
Reclosing Relay Open Interval Time-Out
in Figure 6.2 is the logic input that is qualified by SEL
OGIC control equation
setting 79CLS, and then propagated onto the close logic in Figure 6.1 to
automatically reclose a circuit breaker. The explanation that follows in this
reclosing relay subsection describes all the reclosing relay settings and logic
that eventually result in this open interval time-out logic input into Figure 6.2.
Other aspects of the reclosing relay are also explained. Up to four (4)
automatic reclosures (shots) are available.
The reclose enable setting, E79, has setting choices N, 1, 2, 3, and 4. Setting
E79 = N defeats the reclosing relay. Setting choices 1 through 4 are the
number of desired automatic reclosures (see Open Interval Timers on
page 6.14).
Reclosing
Relay States and
General Operation
Figure 6.5 explains in general the different states of the reclosing relay and its
operation.
Figure 6.5 Reclosing Relay States and General Operation
Reset State
Lockout State
All Automatic
Reclosing Attempts
Unsuccessful
Unsuccessful
Reclose Initiation
Other Lockout Conditions
Power Up
Reset
Timer
Times
Out
Reset
Timer
Times
Out
Other
Lockout
Conditions
Unsuccessful
Reclose
Initiation
Successful
Reclose
Initiation
Successful
Reclose
Initiation
Maintained
Lockout
Condition
The circuit breaker has been closed
for a qualifying reset time. The SEL-311C
is ready to go through an automatic
reclosing sequence in the reclose cycle
state if the circuit breaker trips open
and reclose initiation is successful.
Relay Word bit 79RS = logical 1
Front-panel RS LED is illuminated.
Reclose Cycle State
The SEL-311C automatically recloses the
circuit breaker after each successful
reclose initiation and corresponding set
open interval time.
Relay Word bit 79CY = logical 1
Neither front-panel RS LED nor
LO LED is illuminated.
All automatic reclosing attempts are
unsuccessful, reclose initiation is unsuccessful,
other lockout conditions occur, or the SEL-311C
powers up. The relay returns to the reset state
after the circuit breaker is closed, the reset
timer times out, and there are no maintained
lockout conditions.
Relay Word bit 79LO = logical 1
Front-panel LO LED is illuminated.
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