Schweitzer Engineering SEL-351P - Reclosing Relay

Date Code 990215 Close and Reclose Logic 6-11
SEL-351P Manual Técnico
In the above referenced subsection Synchronism Check Elements, note item 3 under
Synchronism Check Element Outputs, Voltages V
P
and V
S
are “Slipping.” Item 3 describes a
last attempt for a synchronism check reclose before timer 79CLSD times out (or setting 79CLSD
= 0.00 and only one check is made).
R ECLOSING R ELAY
Note that input:
Reclosing Relay Open Interval Time-Out
in
Figure SECTION 6: .2 is the logic input that is qualified by SEL OGIC Control Equation
setting 79CLS, and then propagated on to the close logic in
Figure SECTION 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 SECTION 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 that follows in this subsection).