Blackout response flowchart
Main busbar
failure
TEST
running
No
Yes
Stop test,
change to
AUTO mode
PMS control
No
Yes
Blackout delay
timer
Blackout
still present
No
Yes
Timer expired
No
Yes
Blackout
resolved
Genset start
sequence and
open TB
Start seq.
OK & TB
tripped
No
Yes
GB close
sequence
GB closed
OK
No
Yes
Blackout
resolved
Alarm
Alarm
No blackout
response
1.
Blackout delay timer:
If the main busbar fails, and the blackout
response is possible, then the
Blackout delay
timer starts.
2.
TEST running:
The controller checks whether a
Test
is running.
If a test is running the controller stops the test and changes to
AUTO mode.
3.
PMS control:
If a test is not running, the controller checks
whether
PMS control
is active. If the controller is under
Switchboard control
there is no blackout response.
4.
Blackout still present:
The controller checks whether the
blackout is still present, and the status of the
Blackout delay
timer.
•
If the blackout is resolved before the timer expires, the
sequence stops.
•
When the timer expires, the genset start sequence and TB
trip sequence start. The order of these sequences depends
on the
Blackout control
parameter. If the genset start
sequence fails, the controller activates the
Start failure
alarm. If the TB trip sequence fails, the controller activates
the
TB open failure
alarm.
5.
Start sequence OK & TB tripped:
After the emergency genset
is started and the tie breaker is open, the controller starts the
generator breaker close sequence.
6.
GB closed OK:
If the generator breaker is closed, the
emergency busbar blackout is resolved.
Power restored
When power is restored on the main busbar, the controller stops the emergency genset according to the flowchart below.
The flowchart is based on
Tie breaker sync. enabled
being
Enabled
. If this parameter is
Not enabled
, then the controller first opens
the generator breaker, then closes the tie breaker.
DESIGNER'S HANDBOOK 4189340911K UK
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