Problem: You have a 208/120V switchboard and want to connect a 240/120V panel to it. When you try, Design Master Electrical tells you that the voltages do not match.
This configuration is common in residential buildings, such as apartments.
Solution: Create the 240/120V panel and any devices connected to it as 208V. Even if the nameplate voltage on the equipment is 240V, it will actually be running at 208V.
If necessary, make notes on the drawing indicating that the equipment is 240V equipment running at 208V.