Energy Costs Should Drive Motor Selection

DN Staff

February 21, 2005

3 Min Read
Energy Costs Should Drive Motor Selection

As energy costs rise, conservation is becoming an important factor in many purchasing decisions. Since energy costs account for more than 94 percent of usage costs over a 10-year operating period, taking power consumption into account is particularly important in industrial motor selections.

Because many end users are switching their existing motors to those with NEMA Premium(TM) efficiencies, like the Baldor Super-E(R) motor family, designers of many types of equipment can gain a substantial marketing edge by paying close attention to electric motor selection. Over 20 years of continuous operation, the actual purchase price will account for only 3 percent of the total operating cost. Energy expenses will be 97 percent of the total, assuming an electrical cost of 7.5 cents per kW-hr.

Determining Energy Costs

Many specifying engineers and other motor specifiers aren't aware of the huge percentage of lifetime costs from energy consumption. But once they start considering it, making comparisons is not difficult.

Determining the actual impact of more efficient motors is a simple task. Baldor's Energy Savings Tool, available free at, provides quick comparisons to existing motors. Users can enter the nameplate data for a motor now being used or considered, and the software will provide performance data for a comparable Baldor motor, showing the difference in overall power consumption and cost. Motor specifiers can also look at many motors at once to determine the plant-wide impact of upgrading to better motors. In a plant with many motorized systems, the benefits ripple out to impact air conditioning costs, which will be lower because premium efficient motors generate less heat losses. Machine designers can use the program to determine the electrical usage for their equipment, allowing reduced operating costs from premium motors and drives to be used as a sales feature. Adding an H2 adjustable speed drive will result in additional energy and productivity savings for many applications.

A Better Built Motor Means Better Savings

If reducing electricity consumption is not enough to attract attention, premium efficient motors also run cooler, extending lifetimes and improving performance. Beyond temperature, other factors play a critical role in long lifetimes. Insulation lasts longer when it's subjected to less heat. Bearing failures, which are responsible for more than half the failures for motors, operate cooler and with less motor-induced vibration in energy efficient motors, so they last longer. Precisely made motors will also have better balance, which will help reduce equipment vibration, improving end product lifetimes while also reducing noise.

The Baldor Super-E motor is designed for use with adjustable speed drives, like the new Baldor H2 series of inverter and vector drives. Its superior insulation system has ISR(R) (inverter spike resistant) magnet wire, phase paper and corona inception testing, the same that is used in Baldor Inverter-Duty and Vector Duty motors. For many typical applications, Super-E motors through 100 hp can operate over a 20:1 constant torque speed range.

Baldor Electric is North America's largest designer, manufacturer and marketer of industrial motors, drives and generators, offering the industry's widest range of NEMA Premium(TM) efficient motors and drives with over 6,500 items available from stock and custom designs available with a 2 week lead time.

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