Liquid hydrofluorocarbons provide low corrosivity lubrication of metallic surfaces especially at elevated temperatures. The phase-to-neutral operating voltage for each phase is at least about 260 volts. The rotor is pivotally fitted between the two faceplates, consisting of a spindle and plural blades, and the spindle has a plurality of cut surfaces for the blades to be respectively secured thereon. In contrast, a dynamic clip art image can be used to represent several similar static clip art images.