Circuit Breakers on Onelines

 

Circuit breakers are used to open or close transmission lines and transformers. They are also used to place generators, loads and switched shunts in or out of service. By default, closed circuit breakers are shown as solid red squares, while open circuit breakers are shown as a green square outline. The color and filled or unfilled properties of circuit breakers can be modified in the Oneline Display Options under Display Object Options. Only those circuit breakers that are set to use the default shape will abide by the shape specified with the Oneline Display Options. Circuit breakers for generators, loads, and switched shunts always use the rectangle shape. Circuit breakers that are automatically inserted for transmission lines and transformers will use the default shape unless the user specifies a different shape.

To change the status of a breaker, left-click on the breaker while in run mode. A circuit breaker directly controls the status of its associated display object. One breaker is shown on the line connecting a generator, load, or shunt to its associated bus. Two breakers are shown by default on transmission lines and transformers. Opening either of the line's circuit breakers opens the transmission line or transformer; you do not have to open circuit breakers at both ends of the line.

Note: Circuit breakers cannot be placed on dc transmission lines.

Edit Mode

By default, when you add a new display object to a oneline diagram, the necessary circuit breakers are automatically added at each end of the branch.

To add a new circuit breaker to the oneline, select Indication > Circuit Breaker from the Individual Insert ribbon group on the Draw ribbon tab and then click the line to which you want to add the breaker. The Circuit Breaker Options dialog will appear with the from and to bus numbers, and the circuit number automatically set to identify the line you selected. Specify the size for the switch and its initial status, as well as whether it will be anchored to the line so that it will move with the line. Click OK to add the circuit breaker, or click Cancel to abort the process. To add more circuit breakers to the line, simply repeat this procedure.

The shape of a branch circuit breaker can be user-specified on the Circuit Breaker Options dialog. If the option to Use Default is selected for the Shape, the shape is dictated by the default circuit breaker shape specified with the Oneline Display Options under the Display Object Options. If a non-default shape is specified that requires an orientation, the Orientation option will be enabled.

To modify the parameters for an existing breaker, position the cursor anywhere on the device and right-click. This invokes the Circuit Breaker Options Dialog, from which you can change many of the breaker's parameters. Additional display settings for the circuit breaker can be accessed by selecting from the Formatting ribbon group.

You can toggle the status of Transmission Line and Transformer circuit breakers while in Edit Mode by right-clicking on the associated line or transformer and selecting Open Line or Close Line from the local menu.

Run Mode

Circuit Breaker status can be toggled in Run Mode by Left-Clicking on a breaker to place its associated object either in or out of service. If the simulation is currently running, any effects of changing a circuit breaker’s status are immediately shown on the oneline.