BECKWITH ELECTRIC M-4272, Instruction Book

Page: 184 / 217

System Setup and Setpoints – 4
4–73
50BF #2 SOURCE 2 BREAKER
FAILURE
Path: System/Setup/Setpoints/50BF#2
The 50BF #2 Source 2 Breaker Failure selection
from the Function Settings group (Figure 4-33) opens
the
50BF #2 Source 2 Breaker Failure dialog screen
(Figure 4-76). The 50BF #2 Source 2 Breaker Failure
Function includes the same features as 50BF #1
except that it monitors for a breaker failure of the
Source 2 breaker and Output 1 for Trip S1 is the
default output setting.
S1 BF SOURCE 1 BREAKER FAILURE
(BREAKER STATUS)
Path: System/Setup/Setpoints/S1 BF
The S1 BF Source 1 Breaker Failure (Breaker Status)
selection from the Function Settings group (Figure
4-33) opens the
S1 BF Source 1 Breaker Failure
(Breaker Status) dialog screen (Figure 4-77).
The Source 1 breaker status inputs are monitored
for breaker failure. The Source 1 breaker is
considered failed when the breaker status has not
changed state within the programmable time after a
trip command is issued.
When the Simultaneous Transfer mode is selected
(Common Function Settings Figure 4-34), and a
breaker failure occurs on Source 1 that should have
tripped, the breaker that was just closed will be
tripped. This prevents the New Source from
continuing to be connected through the failed breaker
to the old source that may be faulted.
If the Sequential Transfer mode is selected
(Common Function Settings Figure 4-34), then a
close command will not be sent since the breaker
status would indicate that the tripped breaker did
not open. Since the transfer could not be completed,
the Incomplete Transfer Lockout timer would time
out and generate a lockout condition.
Enable/Disable — The top right corner of the display
includes a command button that will disable or
enable the function.
Time Delay — (0 to 30 cycles) The Source 1
breaker is considered failed when the breaker status
has not changed state within the programmable
time after a trip command is issued.
I/O Selection — The I/O Selection button opens
the S1 BF Source 1 Breaker Failure Outputs
Blocking Inputs Selection Dialog Screen (Figure
4-78).
This screen allows any input or the Fuse
Loss (FL) function to be selected to block the S1
BF Function. The S1 BF Function can also be used
to activate a selected output when it times out.
Save/Cancel — The Save selection saves the S1
BF Source 1 Breaker Failure (Breaker Status)
settings either to an open file or to the target MBTS.
Cancel, returns the user to the previous open screen.
Figure 4-76 50BF #2 Source 2 Breaker Failure Dialog Screen