7.9
Date Code 20060320 Instruction Manual SEL-311C Relay
Inputs, Outputs, Timers, and Other Control Logic
Local Control Switches
Settings Examples
Local bits LB3 and LB4 might be used for manual trip and close functions.
Their corresponding local control switch position labels are set to configure
the switches as OFF/MOMENTARY switches, as shown in Table 7.3.
Following Figure 7.8 and Figure 7.9 show local control switches with
example settings.
Figure 7.8 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 7.9 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 + . . .
SELOGIC control equation setting CL is for close conditions, other than
automatic reclosing or serial port CLOSE command (see Figure 6.1).
Table 7.3 Local Bits LB3 and LB4 Used for Manual Trip and Close Functions
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
RETURN
(Logical 0)
TRIP
Local
Bit
Manual Trip
Logical 1
LB4
RETURN
(Logical 0)
CLOSE
Local
Bit
Manual Close
To Next Page
