Basler Electric DGC-2020HD - Manual (Page 108)

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across a breaker, the phase AB L-L voltages on the generator side of the breaker must be wired to the
GEN VA and GEN VB terminals on the DGC-2020HD. The phase AB L-L voltages on the bus side of the
breaker (the bus to which the generator will be connected when the breaker is closed) must be wired to
the BUS VA and BUS VB terminals on the DGC-2020HD. See the Typical Connections chapter, for a
three-phase wye connection for typical applications diagram.
In single-phase AC configuration, the synchronizer aligns the voltage on the GEN VA terminal with that on
the BUS VA terminal, and the voltage on the GEN VC terminal with that on the BUS VC terminal. In other
words, the DGC-2020HD aligns the generator phase CA L-L voltage with the bus phase AB L-L voltage.
In order for the synchronizer to provide correct phase alignment across a breaker, the phase CA L-L
voltages on the generator side of the breaker must be wired to the GEN VA and GEN VC terminals on the
DGC-2020HD. An optional wire jumper may also connect the GEN VB and GEN VC terminals together.
The phase CA L-L voltage on the bus side of the breaker (the bus to which the generator will be
connected when the breaker is closed) must be wired to the BUS VA and BUS VC terminals on the DGC-
2020HD. A wire jumper must also connect the BUS VB and BUS VC terminals together. See the Typical
Connections chapter, for a single-phase AC connection for typical applications diagram.
Generator speed can be influenced by the speed trim function, which is active at all times if enabled, and
the synchronizer. Since the speed trim function can cause some activity on the speed bias outputs, when
performing synchronizer troubleshooting it is recommended that the speed trim function be disabled.
Refer to the Maintenance and Troubleshooting chapter for more information.
It is also required that phase rotation is the same on both sides of the breaker for synchronization to be
possible.
When the DGC-2020HD is performing synchronization, the Synchronizer screen is shown on the front
panel. Slip angle, slip frequency, voltage difference, synchronizer active status, and a synchronizer scope
are displayed.
Note
When using the DGC-2020HD synchronizer, it is recommended that
local DGC-2020HD relay outputs be used for breaker closing
commands to minimize the possibility of closures outside of desired
breaker closing angles.
If remote (CEM-2020) outputs are to be used for breaker close
commands, it is recommended that the anticipatory synchronizer type
be used, and the breaker close wait time be adjusted to account for
possible CEM-2020 output delays (typically 50 ms) to achieve desired
breaker closing angles.
Figure 46 illustrates the BESTCOMSPlus Synchronizer screen. Settings are listed in Table 36.
Synchronizer DGC-2020HD