P.12.10
SEL-411L Relay Protection Manual Date Code 20151029
Bay Control
Disconnect Logic
Disconnect Switch Close and Open Immobility Timer Action Inputs
89CCNm, 89OCNm
89CCNm and 89OCNm SELOGIC control equations are for programmable
close and open disconnect switch operations. The LOCAL Relay Word bit
must be deasserted for the SEL
OGIC close or open to initiate a disconnect
switch operation. Use care when using SEL
OGIC control equations for
disconnect switch operations; this disconnect operate method is not
supervised by the breaker jumper or appropriate relay access levels as is the
case with other disconnect operation methods.
89CCMm, 89OCMm
89CCMm and 89OCMm Relay Word bits pulse for one-quarter cycle when
close and open disconnect operations are executed from the one-line diagram
on the front-panel screen. The LOCAL Relay Word bit must be asserted for
Relay Word bits 89CCMm or 89OCMm to assert.
89CCm, 89OCm
The 89CLOSE command or Fast Operate disconnect close message, pulses
Relay Word bit 89CCm for one-quarter cycle. The 89OPEN command or Fast
Operate disconnect open message, pulses Relay Word bit 89OCm for one-
quarter cycle. The LOCAL Relay Word bit must be deasserted for a
disconnect switch operation to be initiated by a Fast Operate message or
89CLOSE and 89OPEN commands.
Disconnect Switch Close and Open Immobility Timer Logic Settings
89CITm, 89OITm
89CITm and 89OITm timer settings in the Bay settings class define the close
and open immobility timers.
Disconnect Switch Close and Open Immobility Timer Logic Outputs
89CIMm, 89OIMm
When 89CIMm or 89OIMm asserts, the close or open immobility timer has
expired.
Disconnect Switch Close and Open Immobility Timer Logic Processing
The Close and the Open Immobility Timer Logic detect when one of the close
or open disconnect switch methods does not initiate successfully. In other
words, it reports when the disconnect switch failed to start moving. The open
and close immobility timer logic circuits are similar. When a close operation
is initiated, the rising-edge-triggered close immobility timer starts timing.
Once the disconnect switch starts to move away from its closed position,
Relay Word bit 89OPNm deasserts (see the Disconnect Switch Status and
Alarm Logic shown in Figure 12.3). If the 89OPNm Relay Word bit deasserts,
the close immobility timer resets and 89CIMm remains deasserted. On the
other hand, if the 89OPNm Relay Word bit stays asserted, the close
immobility timer does not reset. After the close immobility timer expires,
89CIMMm asserts for one second. When 89CIMm asserts, the close operation
is considered to have failed to initiate. 89CIMm is an input to the disconnect
switch status and alarm logic for alarm condition indications.
This logic also uses the LOCAL Relay Word bit to supervise front-panel
operations. With the LOCAL Relay Word bit deasserted, no disconnect
operations can be initiated from the one-line diagram. With the LOCAL Relay
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