Schweitzer Engineering Laboratories SEL-351A - Figure 7.7 Configured Manual Trip Switch Drives Local Bit LB3; Figure 7.8 Configured Manual Close Switch Drives Local Bit LB4

7.7
Date Code 20080213 Instruction Manual SEL-351A Relay
Inputs, Outputs, Timers, and Other Control Logic
Local Control Switches (Only on Models With LCD)
Factory Settings
Examples
Local bits LB3 and LB4 are used in a few of the factory SELOGIC control
equation settings for manual trip and close functions. Their corresponding
local control switch position labels are set to configure the switches as OFF/
MOMENTARY switches:
Following Figure 7.7 and Figure 7.8 show local control switches with factory
settings.
Figure 7.7 Configured Manual Trip Switch Drives Local Bit LB3
Local bit LB3 is set to trip in the following SELOGIC control equation trip
setting (see Figure 5.1):
TR = ... + LB3 + ...
To keep reclosing from being initiated for this trip, set local bit LB3 to drive
the reclosing relay to lockout for a manual trip (see Section 6: Close and
Reclose Logic):
79DTL = ... + LB3
Figure 7.8 Configured Manual Close Switch Drives Local Bit LB4
Local bit LB4 is set to close the circuit breaker in the following SELOGIC
control equation setting:
CL = LB4
SEL
OGIC control equation setting CL is for close conditions, other than
automatic reclosing or serial port CLOSE command (see Figure 6.1).
Local Bit Label Settings Function
LB3 NLB3 = MANUAL TRIP trips breaker and
drives reclosing relay to lockout
CLB3 = RETURN OFF position
(“return” from MOMENTARY position)
SLB3 = ON position—not used (left “blank”)
PLB3 = TRIP MOMENTARY position
LB4 NLB4 = MANUAL CLOSE closes breaker,
separate from automatic reclosing
CLB4 = RETURN OFF position
(“return” from MOMENTARY position)
SLB4 = ON position—not used (left “blank”)
PLB3 = CLOSE MOMENTARY position
Logical 1
LB3
MANUAL TRIP
RETURN
(Logical 0)
TRIP
Local
Bit
Logical 1
LB4
MANUAL CLOSE
RETURN
(Logical 0)
CLOSE
Local
Bit
Courtesy of NationalSwitchgear.com