Schweitzer Engineering Laboratories SEL-251 - Use!L for Inversion; Programming Output Contacts; Viewing Logic Equations; Figure 2.8: Relay Word Bit Realization

2-16 Specifications Date Code 20000421
SEL-251, -2, -3 Instruction Manual
Use !L for Inversion
Variable L is any OR-combination of elements in R1 through R4. The inverse of L (!L) is in the
Relay Word. Also, output contacts A1 through A4 and the ALARM can be configured as either
"a" or "b" contacts for an additional inversion (Conventional Terminal Block Relays only).
Figure 2.8: Relay Word Bit Realization
Programming Output Contacts
Write output equations to define tripping and other control functions.
TRIP: Select any OR-combination of elements in R1, R2, R4, and R6 via the TR(1246)
variable. Direct Trip input and OPEN command also assert TRIP. See Figure 2.24
for information about TRIP output contact operation.
A1, A2: Select any OR-combination of elements in R1, R2, R3, and R4.
A3: Select any OR-combination of elements in R1, R3, R4, and R6.
A4: Select any OR-combination of elements in R2, R3, R4, and R6. Optionally, A4 can
operate as an ALARM by placement of jumper JMP3 (the jumper has positions A4
and ALARM).
The CLOSE and ALARM functions have dedicated outputs:
CLOSE: Asserts by recloser, DC input, or CLOSE command (see Figure 2.25 for an illus-
tration of CLOSE output contact operations).
ALARM: The ALARM output closes for the following conditions:
− Three unsuccessful Level 1 access attempts: 1 second pulse
− Any Level 2 attempt: 1 second pulse
− Self-test failures: permanent contact closure or 1 second pulse depending
on which test fails (see Table 2.5)
− The ALARM output closes momentarily when relay settings, setting groups,
or passwords are changed. It also closes when a date is entered, if the year
stored in EEPROM differs from the year entered (see DATE command).
On Conventional Terminal Block Relays, all output relay contacts may be configured as "a" or
"b" contacts with soldered wire jumpers JMP4 through JMP11 (each jumper has positions A and
B). All relay contacts are rated for circuit breaker tripping duty.
Viewing Logic Equations
Use the SHOWSET command to print all relay settings including the SELOGIC Control Equa-
tions configuration. You can inspect settings in the sample event report in Section 4: Event
Reporting.