Motor selection is a time-consuming process. Each design has a unique combination of factors that need to be evaluated individually to make sure which design is best suited for a given application. DTR Services has been in the electric motors industry for 20 years. Over the years, we have gathered information and have understood how to match the needs of our clients perfectly.
Have a look at the comprehensive list of factors to consider while buying an electric motor:
Each application will have a different requirement for performance. Starting torque, maximum speed and load profile are the three factors that contribute to the performance of a motor. As performance is the most important requirement while choosing a motor, start by narrowing your choices down from here.
The room temperature where the motor is installed affects the performance of the motor. Motors are built to be most efficient between 20 degrees Celsius and 40 degrees Celsius. If the ambient temperature is more than 40 C, the motor would have to be run at a lower capacity to avoid reducing its lifespan due to overloading.
Not all motors are built to be dust resistant or waterproof, so keep in mind to purchase a motor that qualifies for these parameters if necessary. An IP rating indicates the environmental conditions in which a certain build of a motor can function effectively.
Application restrictions of size and weight must be taken into consideration before settling on a choice. Some applications need a long and thin motor while others might need a compact motor that takes up as less space as possible. The size of a motor depends on performance requirements.
Maintenance requirements are one of the main concerns while choosing a motor. Brush type motors are subject to wear and tear the most. So if longevity is a big concern, it is advisable to opt for a brushless motor to reduce downtime and maintenance expenses. For more information on electric motor maintenance, read our blog.
Energy Efficiency Regulations
The NEMA(National Electrical Manufacturers Association) in Canada regulates electrical motor efficiency standards. The NEMA Premium trademark label is issued to only those motors that have passed its stringent quality tests. Look for it while you make your purchase.
Different motor types cater to the different concerns mentioned above. A brief overview of the general types can help you recognize the right motor.
AC motors run on alternating current. They are suited for applications that require continuous and consistent speed. They are efficient and require less maintenance and they have a long life making them a popular choice for industrial usage. However, they are bulky and have a high start-up energy consumption rate.
Based on their power output, there are two main AC motor types:
• Single phase AC motors are used for domestic purposes as they are less powerful and more efficient
• Three phase AC motors are widely used in the industrial environment because they are very powerful
DC motors run on direct current. They are perfect for dynamic applications because their accuracy in speed control is very high, allowing them to start, stop, accelerate or reverse almost instantaneously. The most obvious difference from AC motors is that battery-powered systems can run them in mobile units. Their main disadvantage is that they tend to wear out and are expensive to maintain.
There are two main types of DC motors, they are:
• Brushed DC motors
Brushed DC motors are not widely used because it is more economical to use AC motors as they require far less maintenance. Even for speed control, AC motors combined with frequency inverter are being used as a cheaper alternative because of high replacement costs that come with brushed DC motors. Though brushed DC motors are inexpensive, generate high start-up torque and are easy to control, they are quickly losing market appeal because of their numerous disadvantages that range from inefficiency to unreliable life expectancy.
• Brushless DC motors
Brushless DC motors have no parts that undergo wearing other than the bearings and this makes them easier to maintain. They operate at much higher speeds and are also more efficient and have a longer life. Electronic switching and rotor position determination enabled by an encoder makes brushless DC motors highly suitable for servomotor applications. But they are expensive because they need further installations like gear reducer and controller.
Stepper motors are synchronous, brushless DC motors that convert digital pulses into mechanical shaft rotation. They are used in applications where there is a necessity to precisely control speed, rotation angle and position. They allow open-loop control, which makes the process cost-efficient. They are highly reliable and sturdy, but they have a risk of overheating. They are also known to be hard to control at high speeds and cause resonance problems.
Learning about different motors will help you make a better decision when you purchase an electric motor, but a reliable supplier will be able to guide you to the perfect choice. DTR Services provides electric motors, generators, pumps and all related services throughout Greater Canada. We also offer round the clock repair and maintenance services in Lethbridge.
Contact us today for a free estimate on your electric motor requirements.