Selecting an asynchronous electric motor should not be a decision based solely on catalog specifications. It requires in-depth analysis, evaluation of correct technical parameters, and consideration of individual operating conditions. This blog will help you understand the details you need to consider during the selection process.
What is an Asynchronous Electric Motor?
Electric motors, also known as induction motors, are the heartbeat of the industrial world.
Conveyors, fans, pumps – practically everything that moves and rotates operates with an electric motor. However, for your enterprise to function efficiently, it is crucial to select the correct motor. Proper selection ensures high productivity, energy savings, and a long motor lifespan.
Types of Asynchronous Motors
To ensure the motor performs all its functions at the highest level and meets requirements, it is essential to understand the types of asynchronous motors and their model parameters.
- Squirrel-cage rotor motors – simple and economical
- Wound-rotor asynchronous motors – for high loads
Advantages of wound-rotor asynchronous motors compared to squirrel-cage rotors:
- Simple operation and maintenance
- Unit reliability
- Optimal price segment
🔗 View the catalog of asynchronous electric motors offered by IESCO.
Electric Motor Selection – Criteria
After studying the types and characteristics of motors, it is essential to consider all criteria. This will help you make the right choice and decide in favor of the most suitable model.
Determine the Nominal Speed (RPM) and Torque (Nm)
First, answer these questions:
- What should the electric motor drive?
- What will be the load?
- How many hours will it operate per day?
The nominal speed is usually indicated on the nameplate.
Shaft rotational speed is measured in revolutions per minute (RPM): typical options are 3000, 1500, or 1000 RPM.
Torque (Nm) and revolutions per minute (RPM) are necessary to calculate the power required by the motor. The clearer you understand what the motor will be used for (starting action, constant rotation, or positioning), the better you will be able to select the appropriate type.
Determine the Intensity of Operation
Motor power must match the load. One of the most critical factors is the correct calculation of power, because if the motor’s power is less than required, the motor will operate under stress and may burn out. Conversely, if an electric motor with excessive power is selected, its efficiency will sharply decrease, and it will lose effectiveness.
Imagine how useful an electric motor that operates only 1-2 hours a day would be if your application needs to run continuously 24/7? In such cases, consider:
- Brushed motors are suitable for short cycles (3000–5000 hours).
- Brushless motors handle continuous operation better.
👉 Incorrectly selected power leads to motor overheating or inefficient operation.
Also important to consider: Is variable speed required? – Then consider VFD-controlled motors.
Determine the Frame Size
According to the IEC standard, the most important dimensions are:
A (distance between mounting holes, perpendicular to the motor)
B (distance between mounting holes, parallel to the motor)
C (shaft shoulder to the first mounting hole)
D (output shaft diameter at the drive end – D.E.)
E (shaft length)
H (shaft height)
These parameters are crucial for installation and compatibility with other equipment.
Choose Efficiency Class and Energy Savings
Electric motors convert electrical energy into mechanical motion. The efficiency between electrical and mechanical energy represents the motor’s efficiency.
Since June 16, 2011, most motors on the market must be marked in accordance with the IE directive and classified by efficiency class. The efficiency of electric motors is measured in classes IE1-IE4, where:
- IE1 – Standard Efficiency (EFF2)
- IE2 – High Efficiency (EFF1)
- IE3 – Premium Efficiency
- IE4 – Super Premium Efficiency
From 2025, only IE4 class motors will be permitted for use in new applications. Although this is more expensive initially, the cost is recouped within two years through energy savings.
Consider Installation Space and Mounting Type
Every enterprise offers spaces of different sizes and shapes. If space is limited, such as in AGV systems, it is important to select a motor with a compact or modular design.
Motor mounting options include:
- B3 – Horizontal mounting on the base
- B5 / B14 – Direct mounting to a pump with an external/internal flange
- B35 / B34 – Combined options
Standard motor dimensions are defined by the IEC34-7 standard.
Consider Environmental Conditions
All performance indicators of an asynchronous electric motor change under environmental influence. Proper operation significantly depends on the environment in which it operates. The following factors are important:
- Temperature: Low temperatures require special bearings or heaters.
- Humidity and Liquid: If the motor comes into contact with liquid, an IP protection class, sealing, or special coating is required.
- Food Safety: For use in the food industry, only motors whose materials do not react with food (stainless material, FDA compliance) are required.
- Explosive Environment: Brushed motors should not be used in flammable environments. In such cases, brushless motors are recommended (ATEX standard)
Why Purchase an Asynchronous Motor from IESCO?
✅ Certified European brands
✅ Engineer support and consultation
✅ On-site delivery and installation
✅ 1-year warranty
Correct Choice = Maximum Efficiency
To purchase the model that best suits your needs, you should rely on both your requirements and the knowledge of professionals. Our highly qualified specialists will help you make the best choice.
📞 Contact us at 032 206 01 00 or visit the IESCO showroom to explore the range of asynchronous electric motors available on-site.
