How to Find Buses that are De-energized Due to a Disconnected or Out-of-Service Connection


When a component in a system is placed out-of-service or disconnected, the connected circuit becomes de-energized. To find the buses that became de-energized as a result of the disconnection, the user can run a query to display these buses (The user may also highlight the de-energized buses in the one-line, but the query is more effective especially when there are multiple drawings in the project). Running a query using the "inService" attribute will not be applicable to the connected circuit since the disconnection does not change the buses' attribute to "out-of-service". In this situation, use the Short-Circuit result to identify the de-energized buses.

The following are the steps to setup the query for the specified requirement above:
1. Run the balanced short-circuit study (Note that Unbalanced/Single Phase systems will be ignored)
2. Open the One-line or Component Editor thru the Document menu.
3. Go to Run->Query and create a New query.
4. In the Query Editor, Type the name of the query then select the bus component.
5. Choose the appropriate attribute for short-circuit that corresponds to the selected SC method used on step 1.
6. Set the attribute value to find zero values since the buses are de-energized then click "Insert".
7. Run the query and it would now display the de-energized buses.