Electric motors are some of the most commonly-used pieces of equipment throughout the business world – but they also represent a huge opportunity for minimizing energy and production costs. By simply switching to more efficient and newer models, the U.S. Department of Energy estimates that American companies can measurably reduce their energy usage.
So, what makes high-efficiency motors much more effective than their standard counterparts, and how do you know when it’s time to upgrade your model?
Changes to Design Requirements
As the nation grows increasingly more energy conscious, the government has implemented new programs to establish efficiency throughout various industries. For instance, in 2007, the Energy Independence and Security Act emerged, requiring the overall upgrade of motor efficiency. Since then, designs for motors have evolved in alignment with the levels listed by the National Electric Manufacturers Association (NEMA). Energy-efficient or “premium” motors are now considered up to 8% more efficient than traditional options.
While most general-purpose motors need to meet the new NEMA standards for efficiency, there are many electric motors that go beyond that definition. Manufacturers have improved motor efficiency by lengthening rotor and stator cores, enclosing fans, and implementing more iron and copper material. While premium motors are often heavier and larger than standard options, they also feature:
- Minimized fan-cooling power designs
- Thinner laminations and better steel properties
- Higher slot fill for copper windings
- Improved bearings
By increasing the mass of copper in coil windings and improving fan design, manufacturers have improved electrical conductivity and minimized wasted energy used on windage properties in premium motors.
Changes in Performance
The benefits of high-efficiency motors come down to their exceptional design improvements and efficient manufacturing tolerances. By lengthening the core and improving the efficiency of stator laminations, it’s possible to minimize electrical losses. What’s more, the improved bearings in premium motors improves efficiency and reduces malfunctions, while efficient fan cooling enhances overall performance. High-efficiency motors:
- Reduce windage and other energy losses
- Reduce resistance losses thanks to a better balance of conductive materials
- Reduce core losses thanks to thinner steel laminations
The numerous upgrades in high-efficiency motors create better performance throughout the life of the machinery. Because failure rates are significantly limited, many manufacturers of high-efficiency motors are willing to offer longer warranties for their products, too.
Not only that, but installing a high-efficiency motor can significantly reduce your operational costs. Just switching to a more energy-efficient 25hp motor that runs 16 hours a day at 75% load could save more than $600 per year in energy costs. With all these benefits, why wouldn’t you consider investing in a high-efficiency motor?
Upgrading to a High-Efficiency Model
If you already have a high-efficiency motor that’s still in a serviceable condition, then you might prefer to “rewind” your motor, rather than replace the unit. Sometimes rewinding can cost as much as 30% less than replacing your motor and when the rewinding is performed by an EASA Accredited facility, the as-designed efficiency is maintained if not improved plus there’s the opportunity to perform reliability enhancements. However, you’ll need to consider updating to a premium efficiency motor if your model is outdated and inefficient.
Premium efficiency motors, if available, can be the best solution for situations where the annual operation of motors goes over 2,000 hours or the motor repair cost exceeds the cost of a new motor. Usually, this will mean that replacing your motor will be less expensive overall than repairing it, provided the repair facility has identified the cause of failure and corrective measures, if possible, are performed. Additionally, you may find that the energy savings allow a generally longer life and more reliable performance from your motor.
Contact Sloan Electric today to arrange an appointment with one of our experts who can assess your motor needs and help you reduce your energy losses.