Basler Electric DECS-250N - Manual (Page 69)

9440500990 Rev D 53
DECS-250N Protection
selected power input configuration C is shown as a read-only value. Power input failure pickup and trip
elements in BESTlogicPlus can be used in a logic scheme to initiate corrective action in response to the
condition. BESTCOMSPlus power input failure settings are illustrated in Figure 39.
Figure 39. Power Input Failure Protection Settings
A Time Delay (s): Adjustable from 0 to 10 seconds in 0.1 second increments.
B Mode: Select Disabled or Enabled.
C Power Input Configuration: Read-only value
Sync-Check Protection
BESTCOMSPlus Navigation Path: Settings Explorer, Protection, Sync Check (25)
HMI Navigation Path: Settings, Protection, Sync Check (25)
Caution
Because the DECS-250N sync-check and automatic synchronizer
functions share internal circuitry, the sync-check function is not
available when the automatic synchronizer style option is selected.
When enabled A , the sync-check (25) function supervises the automatic or manual synchronism of the
controlled generator with a bus/utility. During synchronizing, the 25 function compares the voltage B , slip
angle C , and slip frequency D differences between the generator and bus. When the generator/bus
differences fall within the setting for each parameter, the 25 status virtual output asserts. This virtual
output can be configured (in BESTlogicPlus) to assert a DECS-250N contact output. This contact output
can, in turn, enable the closure of a breaker tying the generator to the bus.
An angle compensation E setting is provided to offset phase shift caused by transformers in the system.
For more details on the angle compensation setting, see the Synchronizer chapter.
When the Gen Freq > Bus Freq F setting box is checked, the 25 status virtual output will not assert unless
the generator frequency is greater than the bus frequency. Sync-check protection settings are illustrated
in Figure 40.