The most important class of three-phase load is the electric motor. A three phase induction motor has a simple design, inherently high starting torque, and high efficiency. Such motors are applied in industry for pumps, fans, blowers, compressors, conveyor drives, and many other kinds of motor-driven equipment. A three-phase motor will be more compact and less costly than a single-phase motor of the same voltage class and rating; and single-phase AC motors above 10 HP (7.5 kW) are uncommon. Three phase motors will also vibrate less and hence last longer than single phase motor of the same power used under the same conditions.