To place a pole with an assembly, but no cables:
Select the Pole tool on the toolbar, and place a new pole at a location
Click Add assembly under Attach Points in the Properties tab
Once Add Assembly has been clicked, click on construction to make the crossarm
Then model the construction and non structural components as desired.
Note that multiple assemblies/non structural components can be added to a single pole however, each time a different construction is desired a new construction must be made by copying the default no cable assembly and editing that.
