Schweitzer Engineering Laboratories SEL-351-5, Instruction Manual

Page: 239 / 706

Date Code 20070117
Instruction Manual SEL-351-5, -6, -7 Relay
Section 6
R.Instruction Manual
Close and Reclose Logic
This section is made up of three subsections:
Close Logic
This subsection 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-351 Relay is to close the
circuit breaker for other close conditions (e.g., manual close initiation via
serial port or optoisolated inputs), then this subsection is the only subsection
that needs to be read in this section (particularly the description of SEL
OGIC®
control equation setting CL).
Reclose Supervision
Logic
This subsection 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
This subsection 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 on page 6.5 ).
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).