Basler Electric DGC-2020ES - Manual (Page 58)

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generator and the mains breakers are configured and open, the DGC-2020ES closes the generator
breaker if the generator side of the breaker is stable or dead. If both breakers are configured and the
mains breaker is closed, the DGC-2020ES will not close the generator breaker.
Before the mains breaker can be closed, it must be configured in BESTCOMSPlus. If both the mains and
the generator breakers are configured and open, the DGC-2020ES will close the mains breaker if the
mains side of the breaker is stable. If both breakers are configured and the generator breaker is closed,
the DGC-2020ES will not close the mains breaker.
Command Agreement
A breaker will not change state if it receives conflicting commands. In other words, if an input is indicating
an open command at the same time another input is indicating a close command, the breaker will not
change state.
Breaker Configuration
The following paragraphs describe how to properly configure a DGC-2020ES for generator breaker
control.
Initial System Setup
Connect the DGC-2020ES according to the appropriate figure in the Typical Connections chapter for the
type of generator connection desired (wye, delta, etc.).
Set up the basic system parameters that will govern engine operation and alarm and pre-alarm
annunciation. Details can be found in the Configuration chapter.
Breaker Hardware
Configure the generator breaker parameters on the BESTCOMSPlus Settings Explorer, Breaker
Management, Breaker Hardware screen. If using the front panel, navigate to Settings > Breaker
Management > Breaker Hardware. Figure 18 illustrates the BESTCOMSPlus Breaker Hardware screen.
1. Mains Fail: When two breakers are configured (enabled), the DGC-2020ES can be enabled to
automatically transfer load power from the mains to the genset during a mains failure. This feature
also enables the DGC-2020ES to transfer the load back to the mains once mains power is restored.
Settings include a transfer delay, return delay, max transfer time, and max return time.
a. When enabled, Reverse Rotation Inhibit prevents automatic load transfer due to a mains
failure when the machine is determined to have reverse phase rotation.
b. If the in-phase monitor is enabled and the Mains Fail Return Delay time has expired, the
generator waits until it detects that the phases are aligned between the generator and the
mains before performing the open transition from the generator back to the utility.
2. Breaker Close Wait Time: This is a time interval in which it is expected that the breaker will transition
from open to closed or closed to open. If the generator breaker does not change state within that
time, either a Gen Breaker Close Fail alarm or Gen Breaker Open Fail alarm is annunciated. If the
mains breaker does not change state within that time, either a Mains Breaker Close Fail alarm or
Mains Breaker Open Fail alarm is annunciated.
3. Generator Breaker
a. Set the Contact Type and Open/Close Pulse Times if pulsed contacts are used.
b. Set the Breaker Closing Time.
4. Mains Breaker
a. Set the Mains Breaker as Configured if it is used, otherwise do not configure these settings.
b. If the mains breaker is configured, set the contact type and pulse times if pulsed contacts are
used.
c. If the mains breaker is configured, set the breaker close time.
Breaker Management DGC-2020ES