The IEC has defined a new standard for testing and rating high-efficiency motors. So, what’s changed and how will it benefit you?
Today, about 30 million new electric motors are sold each year for industrial purposes, while some 300 million motors are in use in industry, infrastructure and large buildings. Together, they are responsible for approximately 40 % of the electricity used globally to drive pumps, fans, compressors and other mechanical traction equipment. With the moral and legal pressure on end users to reduce carbon footprint, and the commercial pressure to reduce costs, it’s no wonder that the focus of manufacturers is on the production of high-efficiency products.
The question is – how can users tell the efficiency of a motor, and how do they know that they can trust any ratings provided by the manufacturer? This is where international standards come in. Until recently, the original European efficiency classification scheme for low voltage AC motors (backed by manufacturers representing 80% of the European production of standard motors ) has remained in use. The scheme established three efficiency classes: EFF1, EFF2 and EFF3, with EFF1 being the highest efficiency class.
This has now been replaced with a new IEC standard (IEC/EN 60034-30). Designed to tighten up testing procedures, it will provide manufacturers with a way to rate their products more accurately in terms of efficiency values. IEC 60034-30 defines energy efficiency classes for single-speed, three-phase, 50Hz and 60Hz, cage-induction motors and comes into force in Europe on 1st January 2010.
New testing rules
Defining new rules concerning the testing methods to be used for determining losses and efficiency, the latest testing standard (IEC 60034-2-1) covers a wider range of motor technologies than its predecessor, and will be based on actual losses in the motor, as opposed to estimated losses. The efficiency class and motor efficiency, tested according to IEC 60034-2-1 at nominal load, will be printed by the manufacturer on the rating plate and given in the written product documentation and catalogue.
The new IE code has a number of advantages over the EFF classifications, such as the ability to signal future best-in-class motors and compare emerging motor technologies with existing technologies in a consistent and fair manner. Previously, additional load losses of a motor were estimated at 0.5% of the input power at rated load. The new standard allows these additional losses to be measured. WEG adopts this rating method – the most rigorous available, ensuring its customers have the most accurate assessment of energy efficiency available.
Efficiency levels
Three commercial levels of energy efficiency as defined in IEC 60034-30 (2008):
Premium Efficiency IE3 (NEMA Premium)
High Efficiency IE2 (EPAct, Eff1)
Standard efficiency IE1 (Eff2)
The standard also mentions a future level above IE3 called IE4 Super Premium Efficiency. However, these products are not yet commercially available and might extend beyond AC induction motor technology. There are still lower efficiency motors in use now (i.e. Eff3), but they will not be used anymore in the new classification.