OMRON Inverters use an oversized power module that can output 200% of the motor's rated output, so it is not necessary to select an Inverter that is one class higher.

On the other hand, there are some cases in which it is better to select an Inverter that is one class higher, even if an OMRON Inverter is being selected.

Examples:
Applications with a large amount of regeneration
Applications operating continuously with high torque at low speed (such as a load moving slowly on a vertical axis)