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 Page 341 of 521
To Next Page
Loading...
