Basler Electric DGC-2020HD - Manual (Page 143)

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Block input is true, the 47 element is disabled. The Trip output is true when the 47 element is in a trip
condition.
Figure 71. Phase Voltage Imbalance Element Logic Block
Operational Settings
Phase voltage imbalance element operational settings are configured on the Phase Voltage Imbalance
settings screen (Figure 72) in BESTCOMSPlus. Setting ranges are defined in the Specifications chapter.
Figure 72. Settings Explorer, Generator Protection, Voltage, Phase Imbalance
Vector Shift (78)
Two vector shift protection (78) elements protect the generator by disconnecting it from the grid when a
loss of mains or mains failure occurs. This prevents the generator from remaining tied to the mains if the
mains returns due to an external reclose device. Vector Shift elements are available only in styles
xxExxxxxx of the DGC-2020HD.
The two, identical vector shift protection elements are designated 78-1 and 78-2. Element logic
connections are made on the BESTlogic
™Plus screen in BESTCOMSPlus® and element operational
settings are configured on the Vector Shift settings screen in BESTCOMSPlus.
BESTCOMSPlus Navigation Path: Settings Explorer, Generator Protection, Loss of Mains Protection,
Vector Shift (78)
Front Panel Navigation Path: Settings Explorer > Protection > Settings Group x (where x = 0 to 3) >
Loss of Mains Protection > Vector Shift (78)
Element Operation
When a loss of mains occurs, it is likely that the generator load will shift abruptly since the generator is
driving everything between the generator output and the utility breaker that removed mains power. Such a
load shift is likely to cause a speed shift, which may result in the generator being out of phase with the
DGC-2020HD Generator Protection