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Setting the Default Breaker Size for Panels

Posted on April 1st, 2010. Last updated on June 14th, 2023.

Design Master Electrical uses the smallest standard breaker as the default breaker size for panels. Circuits with no load attached will have breakers of this size.

To set the default breaker sizes, use the Wire Sizing command.

In the grid at the bottom of the dialog box, there are three columns for setting standard breaker sizes:

  • Standard Branch Circuit: This breaker size is automatically used when sizing standard branch circuits.
  • Equipment Branch Circuit: This breaker size is automatically used when sizing equipment connection circuits.
  • Standard Feeder: This breaker size is automatically used when sizing distribution equipment feeders.

The breaker sizes that are checked here are used when automatically sizing breakers. The smallest one is used as the default.

Often, a project requires 20A breakers at minimum, but the project is inserting 15A breakers. To fix this, run the Wire Sizing command and uncheck the boxes for the 15 amperages. The breakers will update the next time loads are calculated.

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