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6.7
Date Code 20171006
Instruction Manual
SEL-400 Series Relays
Autoreclosing
One-Circuit-Breaker Autoreclosing
3PLSHT Deasserted (Three-Pole Shot Remains)
The recloser exhibits three possible state transitions when 3PLSHT is not asserted:
➤
If no further trip conditions occur, the recloser goes to the reset state
BK1RS after timer 3PRCD expires.
➤
If a fault occurs during the 3PRCD reclaim time, then the recloser
asserts Relay Word bit 3PARC if all three-pole reclose conditions are
satisfied (E3PR1 is logical 1, for example) and returns to the
beginning of the 79CY3 cycle state; the recloser increments the shot
counter and begins the next open interval timer.
➤
If a fault occurs during the 3PRCD reclaim time, and the three-pole
reclose conditions are not satisfied (E3PR1 is logical 0, for example),
the recloser exits the 79CY3 cycle state and goes to the lockout state
BK1LO.
Lockout State From 79CY3
The recloser goes to lockout (BK1LO) when any of the following occur:
➤
The number of trips exceeds the maximum number of shots
(N3PSHOT)
➤
Supervision condition 3P1CLS fails to assert in BK1CLSD time
➤
Relay Word bit 3POLINE asserts (for a circuit breaker manual
opening)
➤
The circuit breaker fails to close within BK1CFD time
➤
Relay Word bit 79DTL asserts
Single- and Three-Pole Mode
NOTE:
Single- and three-pole mode
is only supported in breakers that
provide single-pole breaker control.
The single- and three-pole mode (SPAR/3PAR) uses elements of both the single-
pole mode (SPAR) and the three-pole mode (3PAR). Reclosing begins after a sin-
gle-pole trip in the single-pole cycle 79CY1 with a valid SPARC as described in
. The recloser closes the circuit breaker and pro-
ceeds to the reclaim timer SPRCD. If a fault occurs during the SPRCD reclaim
time and SPLSHT is asserted, then the recloser asserts Relay Word bit 3PARC if
all three-pole reclose conditions are satisfied. Upon asserting 3PARC, the
recloser exits the 79CY1 cycle state and goes to the beginning of the three-pole
autoreclose cycle state 79CY3. The recloser proceeds through the 79CY3 state
and exits this state as described in
.
Three-Pole Priority
If a single-pole autoreclose cycle 79CY1 is in progress and the relay receives an
initiation for three-pole reclosing 3PRI, the recloser immediately starts a three-
pole autoreclose cycle 79CY3.
Active Circuit Breakers
Two Relay Word bits describe when Circuit Breaker 1 is active for the autore-
close logic:
➤
NBK0, No Breaker Active in Reclose Scheme
➤
NBK1, One Breaker Active in Reclose Scheme
Summary of Contents for SEL-421-4
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