Yes
GB open
command
Open
conditions
OK
No
Yes
GB
closed
No
Yes
Deload genset
Load < open
set point
No
Yes
Deload
timer
expired
No
Yes
Open GB
GB opened
No
Yes
GB opened
Command
and mode
match
No
Yes
Info message
Info message
Info message
Alarm
Alarm
1.
Command and mode match:
The controller checks
that the command source and the controller mode
match:
•
In AUTO mode, the power management system
must send the command to open the generator
breaker. The controller ignores all other external
commands.
•
In SEMI mode, the command to open the genset
breaker can come from the following:
◦
The operator can press the push-button
Open
breaker
on the display unit.
◦
The operator can use PICUS to send an open
breaker command.
◦
The command can come from an external
source, like a PLC.
2.
Open conditions OK:
The controller checks whether
the open conditions are OK. The following conditions
must be met:
•
The system must have at least one other source of
power running and connected to the busbar (for
example, another genset, a shaft generator or a
shore controller).
•
The remaining gensets must not be overloaded after
the breaker opens.
3.
GB closed:
The controller checks whether the
generator breaker is closed. If the generator breaker is
open, the sequence ends.
4.
Deload genset:
The power management system de-
loads the genset:
•
When the load is less than the set point for the
breaker to open, the controller activates the
Generator breaker > Control > Open
output.
•
If the controller cannot de-load the breaker before
the de-load timer expires, the controller activates the
GB de-load failure
alarm. The controller continues to
try to de-load the breaker.
5.
GB opened:
The controller checks whether the
generator breaker has opened:
•
If the generator breaker has opened, the generator
breaker open sequence has been completed
successfully.
•
If the generator breaker has not opened, the
controller activates the
GB opening failure
alarm.
8.5.5 Generator breaker trip flowchart
The controller automatically trips the generator breaker (GB) for these alarm actions:
•
Trip generator breaker
•
Trip generator breaker and stop engine
•
Trip generator breaker and shutdown engine
The generator breaker also trips if the controller's
Emergency stop
input is deactivated.
The controller does not require the genset stop conditions to be met for a breaker trip. Similarly, the breaker is not de-loaded for a
trip.
DESIGNER'S HANDBOOK 4189340911K UK
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