Table 10.8
Shaft generator breaker close sequence for starting PTH
SGB close
signal
Power take
home input
No
Yes
Normal SGB
close sequence
PTH
connect load
available
No
Yes
SGB
open
No
Yes
Sync the busbar
with the PTH
shaft generator
Synchronised
No
Yes
Sync timer
expired
No
Yes
Close SGB
SGB closed
No
Yes
SGB closed
Info message
Alarm
Alarm
Start more
gensets
No
Yes
Info message
V&Hz
within
limits
No
Yes
Info message
The following conditions must be met to successfully start
PTH:
1.
Power take home input:
The
Power take home
input
must be activated and the shaft generator breaker must
be open.
2.
V&Hz within limits:
The controller checks that the
busbar and shaft generator voltage and frequency are
within the required range.
3. The operator must ensure that the shaft generator
frequency is within the nominal frequency range. This
may, for example, be done by engaging an electric pony
motor controlled by a frequency converter on the main
drive.
4.
PTH connect available:
The
PTH connect load
must be
available.
5.
Synchronised:
The power management system
synchronises the busbar with the shaft generator, and
closes the shaft generator breaker.
Conditions for stopping PTH
PTH is stopped when the shaft generator breaker receives an
Open
command. The
Open
command could be a digital input, or an
input from the breaker open push-button on the SHAFT generator controller display unit.
DESIGNER'S HANDBOOK 4189340911K UK
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