Sel 411L - Circuit Breaker Failure Protection; Figure 3.159 Trip a Unlatch Logic; Figure 3.160 Trip During Open Pole

P.3.247
Date Code 20151029 Protection Manual SEL-411L Relay
Protection Functions
Circuit Breaker Failure Protection
Figure 3.159 Trip A Unlatch Logic
Figure 3.160 Trip During Open Pole
Circuit Breaker Failure Protection
Use the relay to provide circuit breaker failure protection for as many as two
circuit breakers. The circuit breaker failure protection logic includes the
following schemes:
➤ Failure to interrupt fault current for phase currents
➤ Failure to interrupt load current
➤ No current/residual current circuit breaker failure protection
➤ Flashover protection while the circuit breaker is open
All schemes can incorporate single-pole and three-pole retrip. Single-pole and
three-pole initiations are available for circuit breaker failure, including
extended breaker failure initiation. The circuit breaker failure logic also
includes breaker failure trip latching logic.
The failure-to-interrupt-fault-current logic includes two schemes; both are
suitable for three-pole or single-pole tripping applications. Scheme 1 is basic
circuit breaker failure that is useful for most applications. Scheme 2 allows
you to have different breaker failure times to differentiate between single-pole
0
1
CYC
3PT
LOPHA
TULO := 1
TULO := 2
52AA1
52AA2
TULO := 3
LOPHA
LOPHB
LOPHC
ULTRA
TULO := 4 Do not run this logic. ULTRA=0, ULTRB=0, ULTRC=0
Relay
Word
Bit
Relay
Word
Bit
Relay
Word
Bit
Relay
Word
Bits
Setting
Setting
Setting
NUMBK=2
1/8 CYC
TOPD
0
1/8
CYC
Relay
Word
Bit
Relay
Word
Bits
TOP
SPT
TPA
TPB
TPC
E3PT
SELOGIC
Setting