Basler Electric BE1-BPR - Manual (Page 42)

2-18 BE1-BPR Application 9272000990 Rev J
Figure 2-20. BFL2E Logic
Breaker Failure Logic 3 for Enhanced Relays (BFL3E)
BFL3E logic (shown in Figure 2-21) provides the following application features.
1. Three-Pole Tripping BF Logic (Features: Input/Output latch-in provided and Control timer limits
operational window). Three BFI inputs are available at IN3, IN4, and IN5 to start delay timer T1. If the
BFI inputs are not reset by the time timer 1 times out and either the phase (F1) or neutral (F2) fault
detector is picked up, BFO1-2 (OUT1-2) closes, tripping the backup breakers. A control timer (T3) is
used to limit the breaker failure window of opportunity and latch-in the BFI inputs. Refer to the breaker
failure timing diagram in Section 1 for information on setting the delay and control timers.
2. Single-Pole Tripping BF Logic (Features: Input/Output latch-in provided and Control timer limits
operational window). If single-pole tripping is used, a BFI input is available (IN6) to start delay timer
T2. This input is only supervised by the phase fault detector (F1). If the BFI input (IN6) is not reset by
the time the timer T2 times out and the phase fault detector (F1) is picked up, BFO2 output closes,
tripping the backup breakers. Control timer, T3 is used to limit the breaker failure window of
opportunity. Refer to the breaker failure timing diagram in Section 1 for information on setting the
delay and control timers.
Neutral fault detector (F2) is not used to supervise the single-pole BF logic because F2 is still picked
up by the phase imbalance after the fault clears. Three-phase BF logic is inhibited during this period
because there is no 3-phase BFI input active. For single-pole tripping, the phase pickup (PU1) must
be set above maximum load levels.
3. Trip Coil Status Monitor. Preprogrammed logic is provided using IN1 to provide breaker status and
IN2 for trip coil continuity. Refer to Application Data in this section for further details on the circuit
operation.