Electric motors power everything from household appliances—like microwaves and refrigerators—to industrial equipment—such as forklifts and power drills. If you’re wondering how an electric motor works, you’ve come to the right place. We have created an outline of the purpose of electric motors, operating procedures, types, advantages, and disadvantages.
Table of Contents
How Electric Motors Work
Electric motors are machines that convert electrical energy into mechanical energy. The created mechanical energy can be utilized to power various types of household appliances and commercial heavy-duty machines. Electric motors have electric charges with either alternating current (AC) or direct current (DC). The electric charge in a direct current follows a one-way path. The electric charge in an alternating current changes directions as it flows. Electric motors have a magnetic foundation, and the magnets create constant internal movement.
Operational Procedures & Components
If you’ve ever asked yourself, “How does an electric motor work?” we have the answer. An electric motor consists of a three-sided electromagnetic field and a magnet. The three-sided electromagnetic field has a positive charge on one side and a negative charge on the other side. The electromagnetic field in an electric motor has a small attachment that holds up the magnet in the middle of the field. Like the electromagnetic field, the magnet has a positive charge on one end and a negative charge on the other end.
As with everyday magnets, an electric motor’s magnet works by attracting opposite charges and repels like charges. The magnet's charges attract and repel the charges of the electromagnetic field. The attracting and repelling of the charges cause a rotating motion in the motor. When the positive end of the magnet repels the positive end of the electromagnetic field, the positive end of the magnet gets pushed in a 180-degree motion to the negative side of the electromagnetic field. This process occurs in all electric motor types.
An electric motor is unique in that once the magnet completes the 180-degree motion, the entire electromagnetic field flips to begin another 180-degree motion of the magnet. As this process repeats, it results in the constant 360-degree motion of the magnet within the electromagnetic field.
2 Types of Electric Motors
1. PMDC Electric Motors
PMDC stands for Permanent Magnetic Direct Current. With all DC motors, an armature revolves within a magnetic field. An armature consists of every part of the motor other than the surrounding magnetic field. A PMDC electric motor is a specific kind of DC motor and contains the following parts:
- Rotor coils
- Stator magnets
The main difference between a PMDC motor and an average DC motor is that the PMDC motor’s magnet is permanent while the DC motor’s magnet is temporary. Since the PMDC magnet is permanent, it can’t receive any external control or maintenance.
The stator in a PMDC electric motor—the barrel surrounding the armature—contains two positive and two negative charges. The two positive charges and two negative charges face each other from opposite directions. The main function of a PMDC motor is to create a mechanical force. This mechanical force works when a current-carrying conductor enters an electromagnetic field.
2. AC Electric Motors
An AC motor uses alternating current instead of direct current to create mechanical energy. The phase level of an AC motor determines whether it’s used in residential or industrial settings. Homes use lower-phase residential AC motors because household appliances require less voltage. Commercial facilities and similar settings use higher-phase industrial AC motors because heavy-duty machines require more voltage. An AC motor includes the following components:
- Solid axle
- Squirrel cage
The stator in an AC electric motor works by causing the electromagnetic field to revolve. This piece contains the metal axle, coils, and squirrel cage. The stator has multiple coil stages, and the outer coils receive electricity directly. The rotor in an AC motor receives power from the stator rather than from an external power source. When the rotor comes in contact with the electromagnetic field, the rotor begins revolving. Unlike the constant revolving motion in PMDC motors, the rotor in an AC motor plays “catch-up” with the current’s speed. This “catch-up” process creates the consistent revolving motion of the rotor.
Unlike PMDC motors, AC motors can be controlled externally. They require either manual or contactor starters to start and stop the motor. The different types of contactor starters include star-delta starters, autotransformer starters, rotor impedance starters, and soft starters.
Advantages & Disadvantages of Electric Motors
When deciding which type of motor is right for you, consider the primary advantages and disadvantages of electric motors:
- Cheaper than other motor types
- Longer lifespan
- Require minimal maintenance
- Automatic start/stop functions
- Don’t require fuel or batteries
- Difficult to move
- Requires an exact current and voltage supply
3 Key Electric Motor Parts
While some specific parts vary between the different types of electric motors, every electric motor contains the following key parts:
The rotor is the magnet component of the electromagnetic field. This portion of the electric motor works by attracting and repelling positive and negative charges within the field, causing the rotor to turn in 180-degree increments.
The commutator has two ends that hook onto the axle and allow the electromagnet coils to latch on. The commutator works with the brushes to flip the electromagnetic field.
The brushes are two springs that hook onto the two commutator connections. Along with the commutator, the brushes make the flipping of the electromagnetic field possible.
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- Sizing Guarantee
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Visit our website to discover why our products remain the top choice in the industry. You can also call us at (866) 418-9060 to learn more about our products, warranties, and policies. Or call our automated direct support line at (602) 640-0930. Experience the Phoenix Phase difference today.