Schweitzer Engineering Laboratories SEL-351-5, Instruction Manual

Page: 241 / 706

6.3
Date Code 20070117
Instruction Manual SEL-351-5, -6, -7 Relay
Close and Reclose Logic
Close Logic
The CLOSE (CC) command is not embedded in the close logic. It is included
in the factory SEL
OGIC
control equation settings:
CL =
… + CC
Relay Word bit CC asserts for execution of the CLOSE command. See CLO
Command (Close Breaker) on page 10.36 for more information on the
CLOSE command. More discussion follows later on the factory settings for
setting CL.
If a user wants to supervise the CLOSE command with optoisolated input
IN106 , the following setting is made:
CL =
… + CC * IN106
With this setting, the CLOSE command can provide a close only if
optoisolated input IN106 is asserted. This is just one CLOSE command
supervision example—many variations are possible.
Unlatch Close
If the CLOSE Relay Word bit is asserted at logical 1, it stays asserted at
logical 1 until one of the following occurs:
➤
The unlatch close condition asserts (ULCL = logical 1).
➤
The circuit breaker closes (52A = logical 1).
➤
The reclose initiation condition (79RI) makes a rising-edge
(logical 0 to logical 1) transition.
➤
The Close Failure Timer times out (Relay Word bit CF = 1).
The Close Failure Timer is inoperative if setting CFD = OFF.
Factory Settings
Example
The factory settings for the close logic SEL
OGIC
control equation settings are:
52A =
IN101
CL = LB4 + CC
ULCL = TRIP
The factory setting for the Close Failure Timer setting is:
CFD = 60.00 cycles
See the SEL-351-5, -6, -7 Relay Settings Sheets for setting ranges.
Set Close
If the Reclosing Relay Open Interval Time-Out logic input at the top of
Figure 6.1 is ignored (reclosing is discussed in detail in a following
subsection), then SEL
OGIC
control equation setting CL is the only logic input
that can set the CLOSE Relay Word bit.
In SEL
OGIC
control equation setting CL = LB4 + CC
➤
Local bit LB4 operates as a manual close switch via the front
panel. See
Local Control Switches on page 7.6 and Local
Control on page 11.8 for more information on local control.
➤
Relay Word bit CC asserts for execution of the CLOSE
command. See CLO Command (Close Breaker) on page 10.36
for more information on the CLOSE command.