Electric motors have had a huge impact on the pump industry.
While it is not certain how centrifugal pumps were powered in the early days, it is assumed with reasonable certainty that the power source was not as efficient or reliable as an electric motor. Can you imagine running a pump with a belt and pulley configuration powered by a steam engine?
|Quality assurance testing (0 Turing to rotor OD on a three-phase rotor) 1920-30s. Photo courtesy of Baldor Electric Company.|
Michael Faraday devised a machine that generated electricity from rotary motion (the electric motor), but it took almost 50 years for the technology to reach a commercially viable stage.
In 1895, the first modern electric power plant went online using Nikola Tesla's alternating current (AC) motor (generator). Until then, all other motors had used direct current.
The industry quickly saw the value of AC motor technology, coupling motors to pumping applications.The pump industry now had the ability to efficiently vary the speed of the pump using a stand-alone power source. Here are examples of how electric motors helped advance pump technology:
- Speed/process control using motor pole count
- Compact pump packages
- Vertical pumping technology was developed around electric motors
- High speed pumping technology (steam turbines were the driver of choice)
- Improved pump/system efficiency
- Variable speed technology
- Eddy current drives
- Variable frequency drives
Steam turbine technology could be used in a number of the pump applications listed above. However, in today's energy-conscious society, steam is more costly and less efficient than electricity. The electric motor has become the driver of choice in about 75 percent of all pump systems, but it cannot cure the energy crisis. The focus is now on the total system looking beyond component efficiency.
History of Energy Efficient Motors
1983 Motor industry begins to offer “premium efficient” motors but no standard exists
October 1992 Energy Policy Act of 1992 signed
October 1997 Energy Policy Act of 1992 goes into effect
1998 Consortium for Energy Efficiency establishes premium efficiency standards
August 2001 NEMA Premium® Efficiency Motor Standard Defined
July 2005 Energy Policy Act of 2005
December 2007 Energy Independence & Security Act of 2007 signed
February 2010 Small Motor Rule made by DOE
December 2010 Energy Independence & Security Act of 2007 takes effect