Table 10.4
Shaft generator breaker (SGB) close flowchart
SGB close
command
Close
conditions
OK
No
Yes
SG V&Hz
OK
No
Yes
Sync busbar
with shaft
generator
Synchronised
No
Yes
Sync timer
expired
No
Yes
Close SGB
SGB closed
No
Yes
SGB closed
Info message
Info message
Alarm
Alarm
1.
SGB close command:
The shaft generator breaker
(SGB) close command can come from the following:
•
The operator can press the push-button
Close
breaker
on the display unit.
•
The operator can use PICUS to send a close breaker
command.
•
The command can come from an external source.
2.
Close conditions OK:
The controller checks that the
close conditions are okay:
•
The SHAFT generator controller must not be under
SWBD control.
•
All connected GENSET controllers must be under
PMS control (that is, there must be no connected
GENSET controllers under switchboard control).
•
The busbar voltage and frequency must be within the
nominal range.
•
The nominal power of the shaft generator must be
more than the required power.
3.
SG V&Hz OK:
The controller checks whether the voltage
and frequency from the shaft generator are within the
allowed range. If not, the controller display unit shows an
info message.
4.
Sync busbar with shaft generator:
The Power
Management System tries to synchronise the busbar to
the shaft generator.
•
When the shaft generator and busbar are
synchronised, the controller activates the close shaft
generator breaker output to close the breaker.
•
If the genset and busbar do not synchronise within
the time allowed, the controller activates a
SGB
synchronisation failure
alarm and the breaker close
sequence stops.
5.
SGB closed:
The controller checks whether the SGB
has closed.
•
If the SGB has closed, the SGB close sequence has
been completed successfully.
•
If the SGB has not closed an
SGB close failure
alarm
is activated.
Changing from genset supply to shaft generator
The operator can start the change from genset supply to shaft generator by activating the close breaker sequence of the shaft
generator breaker. The SHAFT generator controller must not be under SWBD control.
If the GENSET controllers are in AUTO mode, after the shaft generator is connected, the GENSET controllers will disconnect and
stop the gensets.
If the GENSET controllers are in SEMI mode, after the shaft generator is connected, the GENSET controllers will not disconnect the
gensets. However, the parallel timer starts when the shaft generator is connected. The GENSET controller trips the generator
breaker when the maximum parallel timer expires.
DESIGNER'S HANDBOOK 4189340911K UK
Page 357 of 521
