Thought leadership What’s in it for you, when it comes to motor independence? Abstract The energy efficiency debate has stimulated motor innovation, reviving and refining outdated technologies to improve efficiency class. The symbiosis of motor innovation and drives technology means that system efficiency class is now a selection criterion for the motor-drive system. However many other factors influence the best choice of drive, such as suitability for retrofit, security of supply, and performance optimization. The article discusses how to choose between bundles and individual components, discussing the benefits and pitfalls of motor-drive bundles and the advantages of drives with universal motor compatibility. Efficiency by rating Motor efficiency is all the rage. These days, plant operators and OEMs routinely specify their electric motor installations according to European or other regional efficiency ratings. In Europe, the IE classification gives an indication of the energy efficiency of the motor and the motor controller (also known as AC drive, variable speed drive, or frequency converter) respectively, and the IES rating defines the efficiency of the entire system of motor and motor controller combined. The practice of specifying IE and IES is so convenient and effective for purchasers and suppliers - and not least, legislators - that it is well on the way to going global in various shapes and forms. More than just IE However, for optimal economy it is vital to be aware that energy and cost efficiency of systems require focus on more than just IE and IES classes. High motor and motor-drive system efficiency is always an excellent argument, but there are other important considerations involved, which should be considered beside the efficiency of the individual motor component or motor-drive system. These factors include logistics, availability, and finally yet importantly, return on investment. All these factors influence total cost of operation: • Flexible logistics • Quick changeover • Freedom from supplier dependency • Coping strategy for difficult locations Furthermore, it is important to realize that the efficiency classes of the motors and motor controller are related to their nominal point. Efficiency classes do not take account of part load efficiencies, even though they represent the majority of the motor operation time. Flexible logistics The first of the “beyond IE” considerations is flexibility. In this context, flexibility means the ability to accommodate changing customer specifications and new technological trends, over the entire lifetime of the application. The best AC drives on the market offer just this: they are compatible with all state of the art motor technologies. Their research experts monitor upcoming new trends and include new motor algorithms in software updates of the drive whenever the potential is good. Quick changeover When the supplier cannot supply a replacement motor as planned, and there are bottlenecks in delivery, a change to an alternative supplier or alternative motor technology is often the best solution. In fact, in the event of both supply bottlenecks and restricted regional access to a specific motor technology, no operator wants to be caught in a vulnerable position. That is when the ability of the drive to adapt to a different motor technology can be priceless. When a dedicated motor technology is not available, for example on a remote site or remote region of the globe, the universally compatible drive saves the day. The best of these drives offer full adaptability to a new motor technology even without the need for special firmware. 1 What’s in it for you, when it comes to motor independence?
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