The Difference is in the Name

Why Use DC Motors Instead of AC Motors?

Much of the time, the decision to use a DC motor instead of an AC motor is based on application and cost. Of course, there are advantages to each type of motor, and markets are present for both types. At Romanoff Industries, we offer a wide spectrum of electric motors and other equipment to meet the demands of our customers’ applications.

Comparing DC and AC Motors

The advantages of using DC motors include:

Speed Control

The DC motor provides considerable speed control below and above the rated speeds. This is carried out for DC shunt motors through methods such as field control and armature control. DC motors are used extensively in fine speed applications involving paper mills and rolling mills.

High Starting Torque

DC series motors are highly suited for applications involving electrical traction utilized for driving heavy loads in starting situations. Motors in the DC series can have starting torques 500% higher than normal operating torques. Applications such as cranes and electric trains utilize DC series motors.

Fast Stopping, Starting, Acceleration, and Reversing

Accurate Steep Minus Speed with Constant Torque

With constant torque drives the motor shaft torque is constant over a particular speed range and the shaft power varies with the speed.

Freedom from Reactive Power Consumption, Harmonics, and Other Factors

For the reasons mentioned above, DC motors are often utilized instead of AC motors in a wide range of applications. This despite the fact that the market for AC motors is larger than that for DC motors. In addition it can be a challenge to find AC motor solutions with fractional horsepower ratings.

Applications for DC Motors

There is increasing demand for 24 and 12V motors to support marine, solar, and portable equipment which is supported readily by DC technology. This technology generally has greater cost-effectiveness than AC for lower horsepower applications. Research and development has not ended when it comes to DC motor technology. Motor companies are continuing to make investments in technology to extend motor life and reduce maintenance costs.

For information about the wide ranging selection of electric motors, transformers, and gear reducers we offer, give our team a call today at 800.366.8778 or send us an email at