Date Code 20080103 Instruction Manual SEL-351S Relay
Section 6
Close and Reclose Logic
This section is made up of three topics:
Close Logic on page 6.2. Close Logic describes the final logic that controls
the close output contact (e.g., OUT102 = CLOSE). This output contact
closes the circuit breaker for automatic reclosures and other close
conditions (e.g., manual close initiation via serial port or optoisolated
inputs).
If automatic reclosing is not needed, but the SEL-351S Relay is to
close the circuit breaker for other close conditions (e.g., manual close
initiation via serial port or optoisolated inputs), then this is the only
topic that needs to be read (particularly the description of SEL
OGIC
®
control equation setting CL).
Reclose Supervision Logic on page 6.7. Reclose Supervision Logic
describes the logic that supervises automatic reclosing when an open-
interval time times out—a final condition check right before the close
logic asserts the close output contact.
Reclose Logic. Reclose Logic describes all the reclosing relay settings and
logic needed for automatic reclosing (besides the final close logic and
reclose supervision logic described in the previous subsections).
The reclose enable setting, E79, has setting choices N, 1, 2, 3, 4, C1,
C2, C3, and C4. Setting E79 = N defeats the reclosing relay. Setting
choices 1 through 4 and C1 through C4 are the number of desired
automatic reclosures. Setting choices 1 through 4 have the reclosing
relay go to the Lockout state upon Reclose Supervision Failure (refer
to Reclose Supervision Logic). Setting choices C1 through C4,
however, do not have the reclosing relay go to the Lockout state upon
Reclose Supervision Failure. Instead, the reclosing relay increments
the shot counter and starts timing on the next open interval. This
operation emulates a rotating drum timer style reclosing relay—going
onto the next open interval time and reclose opportunity if supervising
conditions for the present reclose opportunity are not true.
NOTE: Setting E79 = N defeats the
reclosing relay, but does not defeat
the ability of the close logic described
in the first subsection (Figure 6.1) to
close the circuit breaker for other
close conditions via SEL
OGIC control
equation setting CL (e.g., manual close
initiation via serial port or
optoisolated inputs).
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