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.
The power of simple is manifested in that others were able to build from the foundation Einstein identified and defined. They were able to accomplish things they most likely could not have otherwise. We also have experienced this phenomenon. Consider Ohm law. Georg Ohm did the hard work and broke down the complex to a simple law. We use the principles contained in that law as a starting point to understand the complexities of electricity and circuit dynamics.
The PWM Drive (pulse-width modulated drive) to motor power conductors are typically the most intense noise source in a system. Proper implementation of shielding, grounding, splicing, and treatment of excess cable is essential to reducing noise in your system.
The first thing you will need to discover is whether you are dealing with a three-phase motor. You may already know this from the application, but another giveaway is that the lead wires of most three-phase motors are single colors, not multiple colors, and usually identified with numbers. If, on the other hand, the motor diameter is less than seven inches and has a terminal board, it is most likely a single-phase motor.