6.15
Date Code 20060320 Instruction Manual SEL-311C Relay
Close and Reclose Logic
Reclosing Relay
Figure 6.6 Reclosing Sequence From Reset to Lockout With Example Settings
SELOGIC control equation setting 79STL (stall open interval timing) can be
set to control open interval timing (see Skip Shot and Stall Open Interval
Timing Settings (79SKP and 79STL, Respectively) on page 6.21).
Determination of Number of Reclosures (Last Shot)
The number of reclosures is equal to the number of open interval time settings
that precede the first open interval time setting set equal to zero. The “last
shot” value is also equal to the number of reclosures.
In the above example settings, two set open interval times precede open
interval 3 time, which is set to zero (79OI3 = 0.00):
79OI1 = 30.00
79OI2 = 600.00
79OI3 = 0.00
For this example:
The number of reclosures (last shot) is 2, the number of set open interval times
that precede the first open interval set to zero.
Observe Shot Counter Operation
Observe the reclosing relay shot counter operation, especially during testing,
with the front-panel shot counter screen (accessed via the {OTHER}
pushbutton). See Functions Unique to the Front-Panel Interface on page 11.6.
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 on page 6.1 for more discussion on SEL
OGIC control equation setting
52A. Also see Optoisolated Inputs on page 7.3 for more discussion on
SEL
OGIC control equation setting 52A.)
Setting 79RSD
Qualifies closures when the relay is in the Reclose Cycle State. These closures
are usually automatic reclosures resulting from open interval time-out.
Open Interval Timeout
Shot
Counter
0
52A
79OI1 = 30
Reset State
Trip Close Trip Close Trip
Reclose Cycle State Lockout State
(79OI3 = 0)
79OI2 = 600
(Last Shot = 2)
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