AC vs. DC Electric Motors – Which Ones Are Best?

We always compare and contrast AC electric motors and DC electric motors to determine which one is best. But the answer is not always a clear one, and a lot of times, the one that is the best depends on the type of job you need the electric motor to perform.

Fundamental Differences Between an AC Electric Motor and a DC Electric Motor

Both AC and DC electric motors use the same principle of using an armature winding and magnetic field to generate power. In a DC electric motor, the armature rotates, and the magnetic field does not rotate. In an AC electric motor, the armature does not rotate, and the magnetic field continuously rotates. Two different approaches to get similar results.  Here are some other factors to consider when selecting an electric motor for your project.

DC electric motors for repair at an electric motor repair shop in Atlanta, GA


Electric motors do not have as many moving parts as an ICE motor, so most of the time, either an AC electric or a DC electric motor still cost more than an equivalent internal combustion motor.

In AC electric motors, the motors themselves tend to be inexpensive, but the power circuit and control features are expensive. DC electric motors use commutation, making the motor heavy, bulky and costly, but the power circuit and control features are not expensive.


Industrial DC electric motors tend to be larger and heavier than industrial AC electric motors. This is because DC electric motors tend to be used on machinery that requires a constant, steady flow of power. Some examples of devices powered by DC electric motors include:

  • Vacuum Cleaners
  • Elevators
  • Warehouse Sorting Equipment

Some examples of industrial applications that are better if powered by AC electric motors include:

  • Appliances
  • Computers
  • Conveyor Systems
  • Hydraulic and Irrigation Pumps
  • Fans and Air Conditioners


In general, DC electric motors are easier to install and maintain. AC electric motors are harder to maintain but don’t require a lot of maintenance in the first place.

Speed Control and Braking

AC electric motors can reach speeds as high as 10000 RPM and can be controlled very precisely by changing the frequency of the supply. DC electric motors can reach speeds as high as 2500 RPM and are difficult to control precisely, have slower response times, and change speeds by increasing or decreasing the motor’s voltage.

Tekwell Services Is Your Electric Motor Expert

Whether you need repairs on an AC electric motor or a DC electric motor, Tekwell’s got you covered. We provide a complete suite of repair and preventive maintenance services for both types of electric motors. For more information, give us a call (toll-free) at 1-888-984-4668 or fill out our quick solution form to contact one of our electric motor experts today.