Motor cables are defined as long when the motor frame is not bonded close enough to the drive panel to be considered a single ground plane. To be considered a single ground plane, the parts must be connected by a surface which is no longer than ten times its width.
As a technician, I naturally look at things from a nuts & bolts perspective. As technicians, we understand objects and assemblies. We understand how things come apart and go back together. Is not this what Einstein and Ohm did? They figured out how "it" comes apart, which led to the ability of others to put "it" back together.