A DG or mains controller that has the breaker racked out feature active, will inform the other controllers in the system that the
breaker is open but also that the power source is not available on the busbar.
In the input list from the USW, the tag “breaker racked out” is assigned to specific inputs, see screen shot below.
INFO
Depending on the controller type, GB, TB, MB or BTB -racked out is shown in the input list.
Several conditions have to be fulfilled before the “Racked out breaker” function will come active:
1. Controller should either be in semi-auto or manual running mode
2. Breaker pos. feedback OFF is active, or a position failure on the specific breaker is present
3. The input for racked out breaker is high
If all the above conditions are fulfilled, the status text and the USW will show “BREAKER RACKED OUT”.
INFO
If a position failure or breaker ext. trip occurs while the breaker is racked out and the input for the feature is high, the
alarms will show but the fail class will be inhibited.
The pictures below shows a mains with both MB, and TB racked out, 1 feedback ON and 1 feedback OFF still it is recognised as an
open signal while the breaker racked out input is high.
INFO
It is important to physically check that the breaker is actually racked out/disconnected from the busbar or is physically in the
test position. When the racked out signal is active, no synchronisation is present, and if the breaker is not physically
DESIGNER'S HANDBOOK 4189341275A EN Page 133 of 196
To Next Page
Loading...
Need help?
General
