Plenty of motors are happy to run in one direction. Assembly lines and conveyors run in one direction and rarely, if ever, switch and run in reverse. Other applications require motors to turn in different directions. High-torque electric motors used in robots for positioning products, for example, may need to move back and forth to move a product i. Single-phase motors are common in residential applications, as they only require one phase, or one leg of a standard electrical connection. They are controlled with the injection of a single sinusoidal signal. The speed of the motor is controlled by the number of magnetic poles present and how the voltage applied generates the magnetic field and ca. A three-phase motor does not rely on one sine wave, but three separate signalsthat are 120 degrees out of phase. These motors are much more common in industrial and manufacturing facilities, where three-phase power is widely available. The speed of three-phase motors can also be controlled by VFDs, which can vary the voltage and frequency output to. Single-phase motors are often a bit more difficult to arrange in a reversing fashion, but still can be reversed in a few ways. Inside a typical capacitor-start motor, the capacitor is connected to either the L or the N wire, providing a slight phase shift in the magnetic field for part of the windings. Reversing the L or N supply to the start windi. One specific type of single-phase motor, the shaded pole motor, cannot be easily reversed. The construction of shaded pole motors is lopsided and generates a lopsided magnetic field, meaning the motor favors turning in a specific direction. This eliminates the capacitor and provides a uniquely direction-specific construction. Simply reversing the l.