Sel SEL-787 - Logic Settings (SET L Command); Table 4.27 Enable Settings

4.70
SEL-787 Relay Instruction Manual Date Code 20150130
Protection and Logic Functions
Logic Settings (SET L Command)
CL Close SELOGIC Control Equation
There are two close logic equations within the SEL-787. They are designed to
operate when
SELOGIC control equation close variable setting CLm is asserted
(m = 1, 2) and to unlatch when
SELOGIC control equation setting ULCLm is
asserted. The output of the logic is Relay Word bits CLOSEm.
The relay controls the closing output contact(s) when the Relay Word bit
CLOSEm appears in an output contact
SELOGIC control equation. Assign the
CLOSE bits to desired output relays as required by your application. See
Figure 2.20 for typical close circuit connection.
Set the CLm
SELOGIC control equations to include an OR-combination of all
Relay Word bits that you want to cause the associated close bits to assert. The
factory-default setting already includes all commonly required Relay Word bits.
Unlatch Close Logic
Each of the two close logic equations has an associated unlatch close SELOGIC
equation. Once a CLOSE bit is asserted it is sealed-in until all of the following
conditions are true:
➤ Unlatch Close SELOGIC control equation setting ULCL1 (or
ULCL2) asserts to logical 1.
➤ Relay Word 52A1 (or 52A2) asserts to logical 1.
➤ Close failure Relay Word bit asserts to logical 1.
Close Failure Logic
Each of the two close logic equations includes a close failure detection with an
associated delay setting (CFD1 and CFD2). Set the close failure delay equal to
the longest close time of the breaker plus a safety margin. If the breaker fails
to close, the Relay Word CF1 (or CF2) will assert for 1/4 cycle. Use the CF
bits as desired.
Logic Settings (SET L Command)
Settings associated with latches, timers, counters, math variables, and output
contacts are listed below. Note that SEL
OGIC equations are processed every
quarter cycle while math variable equations and analog quantities are updated
every 100 ms.
SELOGIC Enables
Table 4.27 shows the enable settings for latch bits (ELAT), SELOGIC control
equations (including timers) (ESV), Counters (ESC), and math variable
equations (EMV). This helps limit the number of settings that you need to
make. For example, if you need six timers, only enable six timers.
IMPORTANT: Upon relay initial
power up or Port 1 setting changes or
Logic setting changes, the user may
have to wait as long as two minutes
before an additional setting change
can occur. Note that the relay is
functional with protection enabled, as
soon as the ENABLED LED comes on
(approximately 5—10 seconds from
power up).
Table 4.27 Enable Settings
Setting Prompt Setting Range Default Setting
SELOGIC Latches N, 1–32 ELAT := 4
SV/Timers N, 1–32 ESV := 5
SEL
OGIC Counters N, 1–32 ESC := N
Math Variables N, 1–32 EMV := N