Date Code 20011205
Close and Reclose Logic
6-21
SEL-311B Instruction Manual
The reclose initiate supervision setting 79RIS supervises setting 79RI. With settings:
79RI =
!52A
79RIS =
TRIP
the transition of the 52A Relay Word bit from logical 1 to logical 0 initiates open interval timing
only if the TRIP Relay Word bit is at logical 1 (TRIP = logical 1). Thus, the TRIP Relay Word
bit has to be asserted when the circuit breaker opens in order to initiate open interval timing.
With a long enough setting of the Minimum Trip Duration Timer (TDURD), the TRIP Relay
Word bit will still be asserted to logical 1 when the circuit breaker opens (see Figure 5.1 and
Figure 5.2 in
Section 5: Trip and Target Logic
).
If the TRIP Relay Word bit is at logical 0 (TRIP = logical 0) when the circuit breaker opens
(logical 1 to logical 0 transition), the relay goes to the Lockout State. This helps prevent reclose
initiation for circuit breaker openings caused by trips external to the relay.
If circuit breaker status indication (52A) is slow, additional setting change ULCL = 0 (unlatch
close; refer to Figure 6.1 and accompanying explanation) may need to be made when 79RI =
!52A. ULCL = 0 avoids going to lockout prematurely for an instantaneous trip after an auto-
reclose by not turning CLOSE off until the circuit breaker status indication tells the relay that the
breaker is closed. The circuit breaker anti-pump circuitry should take care of the TRIP and
CLOSE being on together for a short period of time.
Other Settings Considerations
1. In the preceding additional setting example, the reclose initiate settings (79RI) includes input
IN101, that is connected to a 52a breaker auxiliary contact (52A = IN101).
79RI =
!52A
If a 52b breaker auxiliary contact is connected to input IN101 (52A = !IN101), the reclose
initiate setting (79RI) remains the same.
2. If no reclose initiate supervision is desired, make the following setting:
79RIS =
1
(numeral
1)
Setting 79RIS = logical 1 at all times. Any time a logical 0 to logical 1 transition is detected
by setting 79RI, open interval timing will be initiated (unless prevented by other means).
3. If the following setting is made:
79RI =
0
(numeral
0)
reclosing will never take place (reclosing is never initiated). The reclosing relay is effectively
inoperative.
4. If the following setting is made:
79RIS =
0
(numeral
0)
reclosing will never take place (the reclosing relay goes directly to the lockout state any time
reclosing is initiated). The reclosing relay is effectively inoperative.
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