I have a job requiring several of the same power supply. On a few circuits on various power supplies, I am needing to change the output circuit from #14 to #12 wire. Is there an easy way to do this without having to create a different assembly in the data

This should enable you to make that change. It will only apply to the .atp you make it in but it is quick and easy.

Be certain you have a project open.

Open the project device editor.

Select the Tab Panel Circuit Templates (Output). Then filter the template groups for the panel you want.

Select one or more  of the Nac output circuits and clone.

Rename the cloned output

Choose a different wire gauge for the cloned circuit.

Save and close the project device editor.

The FireCAD pallete Circuits tab will now show both the original 14 ga circuit and the new 12 ga circuit. Choose either one.