September 2020

32 September 2020 www.drivesncontrols.com M any electric motors in use today are either low efficiency or not properly sized for their application. Both issues result in the motors working harder than they need to, using more energy in the process. Similarly, older motors may have been rewound several during maintenance, reducing their efficiency. Because energy consumption accounts for 96% of the total lifecycle cost of a motor, paying extra for a premium efficiency machine will result in a return-on- investment over its lifespan. But if the motor has been working for decades, is it worth the hassle of upgrading it? The upgrade process doesn’t need to be disruptive. A pre-defined schedule can ensure that the motor exchange is carried out quickly and with minimal downtime. Opting for standard footprints helps to streamline this process, as the factory layout will not need to be altered. Obviously, if you have hundreds of motors in your facility, it’s not feasible to replace them all in one go. Target those that have been subjected to rewinds first, and plan a schedule of replacements over two to three years to avoid significant downtime. Smart sensors To keep motors running optimally, you can install retrofit smart sensors which can monitor important metrics such as vibration and temperature in real-time. Built-in predictive maintenance analytics can1 identify future problems before any failures occur. These sensors – such as WEG’s Motor Scan – can extract motor data and send it to a smartphone or tablet. One Brazilian manufacturer implemented this technology on motors driving four identical air recirculating machines. When the maintenance team received an alert that one had higher vibration levels than the acceptable threshold, they were able to solve the problem. Without this insight, unexpected factory shutdowns could have arisen. But where are the energy savings in such a case? Firstly, increased vibration increases energy usage. Solid integrated feet on a motor and good mechanical stiffness are crucial to reduce vibrations. By resolving non-optimal performance rapidly, this wasted energy can be minimised. The cost of the energy needed to run an electric motor over ten years is at least 30 times its purchase price. With energy consumption responsible for the vast majority of whole-life costs, WEG’s European marketing manager Marek Lukaszczyk explains several techniques for improving motor efficiencies. Small changes can boost plant efficiency n ENERGY EFFICIENCY Implementing small changes can improve the energy efficiency of your electric motors