When a DC motor is imported as a component of an incomplete or unassembled machine, it may be classified with the complete machine under GRI 2(a) if the essential character of the complete article is present. However, motors imported separately as spare parts or for independent sale are classified in their own right under the motors heading. The specific facts of each shipment determine the outcome, and a binding ruling from CBP can provide certainty.

A regenerative motor can function as both a motor and a generator depending on operating mode. CBP generally classifies such units based on their principal function as declared by the importer and supported by technical documentation. If the unit is designed primarily for propulsion with regenerative braking as a secondary feature, it typically classifies as a motor; if generation is the primary function, it may classify as a generator. Clear OEM specifications are essential to support the chosen classification.