Date Code 20020426 Close and Reclose Logic 6-3
SEL-351-5, -6, -7 Instruction Manual
CL = … + CC
Relay Word bit CC asserts for execution of the CLOSE Command. See CLO Command
(Close Breaker) in Section 10: Serial Port Communications and Commands for more
information on the CLOSE Command. More discussion follows later on the factory
settings for setting CL.
If previous firmware versions of the SEL-351 Relay with the CLOSE command
imbedded in the close logic also have setting CL set as:
CL = … + CC
this would appear as a redundancy in inputting the CLOSE command into the close logic.
But, this is no problem—just a redundancy in logic. Thus, SEL-351 Relays with various
firmware versions can be set the same with respect to setting CL = … + CC.
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.
• Or 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 settings sheets at the end of Section 9: Setting the Relay for setting ranges.
To Next Page
Loading...
