Induction motors are an incredibly useful piece of technology. Induction motors have been around for a long time, but there have been many variations on the original theme over the years. There are different types of induction motor and understanding these can make you an expert at finding the best machine for your needs in both performance and price.
1. Single-phase induction motor
The single-phase induction motor is used in power generation and distribution systems, where the speed of rotation of the motor is measured in revolutions per minute (RPM). It has an iron core that rotates within a magnetic field produced by permanent magnets. The stator windings are arranged in the same direction as the rotor windings, with the poles of both sets of windings aligned with each other. The motor is then connected to a voltage source and powered to rotate at a constant speed.
Commonly used single-phase induction motor types:
- Split phase single-phase induction motor
The split-phase single-phase induction motor is a type of electric motor that uses a split power system to divide the input current into two phases. The split phase method divides the input current into two phases by using an additional stator winding, commonly known as a “shaded pole”. This method can be used in either single or three-phase operations. The most common application for this type of motor is in air conditioning and heating applications where the motor must operate on both AC and DC supplies.
In order to produce electricity, AC power enters one end of the motor and passes through a series circuit (a series connection of electrical components) before exiting at the other end of the motor. While AC power is present at one end of the motor, DC power enters through its opposite end and passes through another series circuit before leaving at its other end. This allows for a single motor to work on both AC and DC systems without any alterations to its design or configuration.
- Shaded pole single-phase induction motor
The shaded pole single-phase induction motor is used in industrial control equipment. It has two poles and a rotor that is mounted on the end of a shaft connected to a drive gear. The motor is driven by the AC field from a variable frequency transformer. The motor’s high torque makes it suitable for heavy-duty applications like elevators and hoists. The shaded pole motors are available with a variety of speed ranges, voltage ratings and power output levels from 1 hp to 300 hp.
- Capacitor Start single-phase induction motor
The capacitor-start single-phase induction motor is mainly used for low-speed applications like lighting fixtures and small appliances. It has three poles and an internal capacitor that generates AC voltage by charging when the power is switched on and discharging when the power is switched off. The capacitor start motors have much lower starting torque than shaded pole motors due to their smaller size; therefore they are often used in applications where space constraints are not an issue such as ceiling fans or small pumps which do not require high starting torque or run continuously at low speeds.
2. Three-phase induction motor
In this type of induction motor, three coils (reference, primary and secondary) are placed inside a brass housing that holds one or more split-phase stepper motors for rotating shafts. The coils are connected to each other through an armature that makes up part of a transformer which produces an alternating current (AC) voltage across them from the AC input voltage from the power utility grid. This AC voltage drives two or more stepper motors whose output shafts drive two or more bearing assemblies (one for each phase).