Basler Electric DGC-2020ES - Manual (Page 57)

9469200990 Rev C 49
Breaker Management
The DGC-2020ES is capable of controlling the generator breaker and the mains breaker. Once it is
determined that a valid breaker request is available, the DGC-2020ES will attempt to operate the breaker
if possible. The user can choose to control only the generator breaker, the generator and mains breakers,
or none. BESTCOMSPlus
® is used to configure breaker management. Refer to the BESTCOMSPlus
chapter for setting information.
Breaker Status
The status of the breakers is determined by using BESTlogic™Plus programmable logic and sent to the
GENBRK and MAINSBRK logic blocks. These logic blocks have outputs that can be configured to
energize an output contact and control a breaker as well as inputs for breaker control and status. See
Breaker Configuration, below, for details on configuring the logic.
Breaker Operation
The DGC-2020ES will attempt to close a breaker only after verifying that it can be closed. If the breaker
cannot be closed, the close request will be ignored. Only one breaker can be closed at a time. Closure to
a dead bus can be performed after meeting dead bus threshold and timing requirements set by the user.
Breaker Operation Requests
Types of breaker operation requests include:
•
Local Request - initiated by internal functions and based on operating modes.
•
Com Request - initiated through a communication port using BESTCOMSPlus or the front panel.
•
Logic Request - initiated from BESTlogicPlus.
The type of response given for a local request depends on the operating mode of the DGC-2020ES.
RUN Mode
When in RUN mode, the generator and mains breakers can be closed manually using contact inputs or
the breaker operation settings on the BESTCOMSPlus Control screen.
OFF or AUTO Mode (Not Running)
If operating in the OFF mode or AUTO and not running, the generator breaker can be closed if the bus is
determined to be dead.
AUTO Mode (Running)
When in AUTO mode and running, the mains fail transfer feature will automatically control the mains
breaker and the generator breaker. Or, the external ATS (automatic transfer switch) will start the
generator and control the breakers itself. In addition, the generator breaker can be automatically
controlled by the exercise timer function or a RUNWLOAD (run with load) start through BESTlogicPlus.
The generator breaker can be manually controlled using contact inputs and outputs or the breaker
operation settings on the BESTCOMSPlus Control screen.
Breaker Closure Conditions
The conditions under which the DGC-2020ES will close a breaker are described in the following
paragraphs.
Breaker Status and Voltage Stability
Before the generator breaker can be closed, it must be configured in BESTCOMSPlus. If only the
generator breaker is configured (mains breaker not configured) the DGC-2020ES reads user settings to
determine if the generator side of the breaker is stable or dead and the bus side is dead. If both the
DGC-2020ES Breaker Management