IE2 is a specific category of three-phase induction motors that have achieved standard efficiency as defined by the IEC 60034-30-1 standards. IE2 motors exhibit better efficiency over the older category of IE1 motors, but do not match the efficiency of newer motors like IE3. Thus, due to either cost, limited availability, or convenience of keeping a legacy system intact, many industries continue to use IE2 motors, even in relatively new machinery. An IE2 motor works well, but it has limitations, especially when operating under excess workloads like higher loads, variable‐speed drives, increased controls on energy costs, and environmental mandates.
Common Failures of an IE2 Motor
An IE2 motor suffers some fatal flaws, most common ones include the following:
- IE2 motors typically use a reduced design allowance in losses. Heat generated by winding resistance, core, cooling inefficiencies or ambient operating temperatures can exacerbate the aging of insulation materials.
- Higher temperatures, in addition to load stresses on the motor and often in combination with a very small misalignment degrade conventional lubricants and bearings.
- Cooling fans added to an IE2 motor often have certain specifics on speed of operation and airflow across the fans. When load is lessened by use of VFD and ventilation around motors is poor, heat can build up and can cause issues.
- The tighter tolerances that characterize IE2 designs for minimizing losses contribute to misalignment, unbalance or mechanical loading. These vary the potential for failure. Vibrations due to coupling, belts or driven equipment propagate less efficient standard designs. If left unchecked, damage to bearings, shafts, and potentially the housing can take place.
Fixing The Issues
Recognizing the problems is only one part of the story when it comes to IE2 motors and the desire to create energy efficient products. Below are some ways on how the issues can be addressed:
Improvements to Cooling and Ventilation
- Ensure defined spacing to allow air to circulate around motors; avoid mounting motors in completely enclosed boxes without airflow around motors.
- Regularly clean the cooling fins, fan guards, and surfaces to provide and maintain proper air flow.
- If your intended operation uses VFD and continued operation at low speed, be sure to consider ancillary cooling fans, or external blowers.
Enhancing Load and Duty Cycle
- Keep continuous operation at or near the rated load to a minimum, unless the motor is selected or designed specifically for service factor. Motors run at an overload capacity build excessive heat.
- Ensure that the motors are right-sized to operate at rated load without being overloaded. Larger motors typically lead to low-load inefficiencies, while undersized motors operate at an overload capacity.
- For variable loads, assess if you can run at a percentage of rated-load that can improve related IE2 efficiency or consider moving to a higher efficiency class when your machine duty cycle demands it.
Improving Power Quality and VFD Use
- When possible, use filters like line reactors, dV/dt filters, properly shielded cables and grounding to mitigate adversely affecting electrical transients.
- When using motors, recommend insulation classes or motor designs that are tested for compatibility when driven by VFD.
- Practice monitoring voltage quality and electrical balance and avoid major voltage imbalance or over or undervoltage conditions.
Use of High-Quality Lubrication and Cleaning Bearing Components
- Always utilize greases that are rated for the operating temperature of the motor. Change lubricant based on conditions at the time of application. Change in the right manner is essential to prevent damage.
- In consideration of ill-affected bearings while running VFD conditioned motors, look at insulated bearing designs or shaft grounding arrangements.
Engage in Routine Maintenance and Condition Monitoring
- Establish a schedule for inspection of routine maintenance for vibration, temperature, noise, bearing condition and others. Early identification of potential issues can significantly avoid major and preventable downtime.
- When available, use thermal imaging or infrared based tools to visually identify any hot spots.
Why The Future Favors Advanced Motors
While an IE2 motor has been an industry staple for a long time, developing trends are still moving systems towards IE3 and above. Some of the reasons behind this shift to energy efficient products include:
- Cost of energy: In an age of increasing energy tariffs, even a small improvement in machine efficiency leads to large savings in operational costs, especially with the use of energy efficient products.
- Regulation and Standards: Both globally and locally we are moving towards more and more regulations encompassing things like ecodesign, energy labels, as well as increased industry standards that are creating a demand for higher efficiency. For various electrical power ranges this means compliance is moving towards IE3 or higher, with respect to energy efficient products.
- Variable Speed Drives and Digital Controls: More and more processes are using variable speed drives, variations in demand, and smart controls, and under these conditions IE2 starts to lag behind new models developed for these very applications.
- Environmental Goals and ESG: Companies are now increasingly audited around their carbon footprint, and with a clear focus on reducing emissions using more efficient motors is the simplest way to contribute towards environmental goals.
LEDL’s Advanced Solutions
Since our establishment in 1983, we at LEDL have consistently broken new ground with our motor innovations. Our IE2 motors, launched at the time they were the most advanced, still serve a number of industries across the globe. Trusted by global leaders, we provide premium quality electric motors, a fact that our IE2 motors, the best in class, fully embody. As inventive leaders, we offer a complete range of motors, including the initial models including IE1 and IE2 as well as the most advanced IE4 and IE5. No matter what your needs, we have a motor for you.
Conclusion
IE2 motors regularly have a place in customer operations through the use of energy efficient products. However, with more and more expectation due to higher loads, tougher environments, tighter regulations, and increased energy costs, IE2 motors regularly suffer from overheating, insulation stress, bearing failure, power quality sensitivity, and limited cooling to name a few. The future motion of the industry and its motors is reliant on reliability, efficiencies, and smart maintenance, and organizations that are proactive at understanding and resolving issues will find themselves realizing lower costs, greater uptime, and more sustainable performance in the industry.
