Sel 751A - CL Close SEL Control Equation; Unlatch Close Logic; Figure 4.30 Close Logic

4.53
Date Code 20100129 Instruction Manual SEL-751A Relay
Protection and Logic Functions
Trip/Close Logic
q From Figure 4.31
Figure 4.30 Close Logic
CL Close SELOGIC Control Equation
The SEL-751A Close Logic offers three ways to close the circuit breaker:
➤ Conditions mapped to CL
➤ Front-panel or serial port (including Modbus and DeviceNet)
CLOSE command
➤ Automatic reclosing when open interval times out (qualified by
SEL
OGIC control equation setting 79CLS—see Figure 4.31).
The relay controls the closing output contact(s) when the Relay Word bit
CLOSE appears in an output contact SEL
OGIC control equation. Default relay
settings have output OUT102 set to CLOSE. See Figure 2.20 for typical close
circuit connection.
Set the CL SEL
OGIC control equation to include an OR-combination of all
Relay Word bits that you want to cause the relay to close breaker. The factory
default setting already includes all commonly required Relay Word bits.
Unlatch Close Logic
Once the CLOSE bit is asserted it is sealed-in until any of the following
conditions are true:
➤ Unlatch Close SELOGIC control equation setting ULCL asserts
to logical 1.
➤ Relay Word 52A asserts to logical 1.
➤ Close failure Relay Word bit asserts to logical 1.
52A
Breaker Status
Close Failure
Timer
CF
Rising-Edge Detect
ULCL
CFD = OFF
Reclosing
Relay
Open
Interval
Time-Out
(qualified
by
79CLS)
79RI
52A
Reclose Initiate
Close
Conditions
(other
than
automatic
reclosing)
q
Unlatch Close
(If setting CFD := OFF, the Close
Failure Timer is inoperative
and does not time limit the
CLOSE output condition)
CL
SELOGIC
Settings
CLOSE
Relay
Word
Bits
Pulses (logical 1)
for one processing
interval if Close
Failure Timer
times out (drives
reclosing relay to
lockout)
Close Failure
CFD
0