Weighing the options
Choosing the right tool for a specific job is a vitally important part of any successful industrial application. However, making the correct choice can also be a difficult challenge. In fact, there are a variety of factors to consider when deciding between electric motors and air motors.
If you’re facing this decision, you’re in luck: Atlas Copco has a comprehensive guide for selecting the appropriate motor for any industrial application.
When trying to pick the best motor for your needs, there are five key factors to consider.
Number one: Torque requirements
Torque is one of the most important measures when it comes to the world of industrial applications. For this reason, air motors are great and dynamic choices. Air motors are designed in a way that allows operators to adjust the torque output to match the exact torque requirement of an application. If and when an air motor is overloaded, the air pressure will simply increase until it bypasses and the needs are met. This process causes no damage to the motor. Essentially, air motors are more versatile and can dynamically load torque to meet your exact application standards.
In contrast, electric motors have fixed torque outputs. While some electric motors can be purchased with multiple speed settings, the torque outputs of the motors cannot be adjusted by operators as needed. If an electric motor is overloaded and a breaker fails to relieve the load, the motor will likely fail prematurely and require replacement.
Number two: Weight of motor
It is also important to note that in many cases a motor plays a large part in the overall weight of an application. For example, the weight of a mixer is determined, in large part, by the weight of the motor. With this in mind, it is clear that a motor’s weight matters and electric motors typically weigh more than their pneumatic counterparts.
Atlas Copco air motors have a high power-to-weight ratio, meaning you can get high power output from our motors for your industrial applications without significantly increasing the weight of an application.
Number three: Speed control needs
Air motors can provide variable and precise speeds when the air control valve is adjusted. While variable speed control options might be available for certain electric motors, it significantly increases the motor’s overall cost. For this reason, if your application requires variable speed control for any reason, air motors will likely be the better choice for you.
Number four: Energy efficiency and costs
One of the biggest differences between air motors and electric motors is in energy efficiency. One drawback of air motors is that they are less efficient than their electric alternatives. This is due to the fact that air pressure — which serves as the energy input in air motors — is lost at different points in the fittings, elbows, and tubes that are necessary for the function of air motors. In some cases, this loss of air pressure can mean that less than 20% of an air motor’s total energy input becomes useable energy for your application.
The cost differences between air and electric motors go hand in hand with the efficiency differences. When comparing the operating costs of the same size air and electric motor units for the same amount of work hours and at the same power cost, it can be more than $1,000 cheaper each year to operate an electric motor.
Number five: Operating environment
The environment in which you plan to use your motor is another important factor to consider when deciding between electric and air motors. Many environments are potentially hazardous for electrical motors. Although explosion-proof electric motors exist, the tight fit between parts that is required to ensure the integrity of the explosion-proof enclosure can cause moisture from condensation to accumulate. This moisture can be corrosive to an electrical motor with moving parts.
Air motors are great choices when working in tough and hazardous environments because they use compressed air as an energy source and do not generate electrical sparks. Atlas Copco air motors, for example, are available in explosion-proof and ATEX certified versions that are perfect for environments where sparks or high temperatures could ignite explosive gases, vapor, or dust. Explosion-proof air motors often also cost less than the electrical equivalent. Finally, air motors can operate safely and optimally in wet or corrosive environments, making them a strong choice when your industrial application requires motors that perform well under any environmental circumstances.
The deciding factor
Every industrial application is unique and only you can determine which factors are most influential when choosing between air motors and electrical motors. Each of the categories listed is worthy of consideration, but the order of importance of each factor is specific to an application.
Air motors are advantageous in particularly hazardous operating environments, when applications must be kept lightweight, and when an application demands dynamic torque output and variable speed control. In contrast, electrical motors are advantageous if your priority is maximizing energy efficiency and minimizing operation costs. Ultimately, careful consideration of the merits of each type of motor and the needs of your specific industrial application will help you decide whether an electrical motor or air motor is right for you.