Design Master can calculate the fault current at all one line devices. This information can be used to set the AIC ratings for these devices, and can also be printed out in a schedule. Design Master will calculate the distances between one line devices based on the locations of these devices on the plan view. These calculated distances may also be overridden by the user.
The fault calculations are based on IEEE Std 242-1975 Recommended Practice for Protection and Coordination of Industrial and Commercial Power Systems. The results are based on a three-phase fault, zero motor contributions, and impedances entered by the engineer to match actual conditions. Default impedances for Design Master are based on the National Electrical Code for conductors in raceway per Table 9. Transformer impedances are for dry-type indoor transformers.
To insert or update the fault current schedule, go to
DM Electrical
One Line SchedulesInsert Fault Schedule
Design Master will ask for the Insertion point for the fault current schedule. Select the location on the drawing for the top left-hand corner of the fault current schedule by clicking.
Design Master will complete the fault current calculations and place the schedule on the drawing.
If there are errors in the one line device definitions, Design Master will alert the user at the AutoCAD command line and specify possible solutions.
A fault current schedule with any errors will be drawn with lines through it.
To update the fault current schedule after any changes to the definition or location of your one line devices, re-insert the schedule the same way you originally inserted it; however, you may press the Enter key to re-insert the fault current schedule in the same location or you may click in a new location if desired. Design Master will update the schedule on the drawing, including deleting the old schedule if you have changed the location when re-inserting.