The ability to understand and calculate the efficiency of an electrical motor is vital in respect to energy conservation, cost savings, and reduced emissions. Industrial customers require this information for applications such as power conversion, conveyer belt motors and water pumps to name a few. Having a method in which to obtain this efficiency calculation, as well as to identify key concerns for improving efficiency in the field is essential to running a successful, safe and efficient operation. On December 19th, 2007, President George W. Bush signed into law the Energy Independence & Securities Act of 2007. This law, which goes into affect on December 19th, 2010, states the mandatory minimum efficiency level for motors is designated by the NEMA Premium Efficiency® Program. Included in this program are all motors previously covered under the Energy Policy Act of 1992 plus the following list: motor ratings 1-200Hp (including u-frame), Design C, close looped pump , footless, vertical shaft-normal thrust, 8-pole and polyphase motors. Also required by this law are those motors ranging from 200-500Hp in the Design B Class. These motors must meet the requirements as stated in NEMA MG-1 Table 12-11.
This white paper discusses why efficiency estimation is important; the parameters that can affect efficiency readings and how these measurements once obtained can be used to the advantage of a motor management specialist.