Electric motors have had a huge impact on the pump industry.
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Improved motor starters help Fabri-Kal achieve its green vision.
For the first time, the United States Department of Energy (DOE) adopted energy conservation standards for small electric motors in February 2010. DOE determined these standards will result in significant conservation of energy, and are technologically feasible and economically justified. Motors covered under these new regulations range from ¼ to 3 hp and include single and poly phase two, four and six pole general purpose motors in NEMA 42, 48 and 56 frames and corresponding IEC equivalent motors and frames. The new regulations will take effect in 2015, which is five years after the original publish date.
It is impossible to balance line-to-line voltages perfectly in a three-phase circuit. In fact, line voltages typically differ by a few volts or more, but a difference that exceeds 1 percent can lead to serious trouble on the plant floor. To maintain peak energy efficiency and thwart premature failure of three-phase motors, install adequate protective devices and periodically check for voltage unbalance at the motor terminals.
Because operational costs ride on efficiency determinations, accurate measurements of losses occurring within the motor are paramount. The reliability of efficiency data is key to any energy-savings plan, and knowing the meaning behind the rating can make or break a smart purchasing decision.
Proper alignment of the pump shaft with the driver can reduce vibration and significantly improve reliability. For appropriate applications, the time, expertise and instruments needed to achieve precision alignment (tolerances of less than 0.005 in) will prevent seal leakage and extend bearing life.
Introduced in June 2010, Super-E Motors with AEGIS Shaft Grounding Ring are used in commercial and industrial applications to drive pumps provides a path to ground for circulating currents, preventing bearing fluting.
When a motor fails, users can (1) rewind, possibly for high efficiency; (2) replace the failed motor with a new motor; or (3) invest in a premium efficiency product. Here are the advantages and disadvantages of each approach and the precautions that must be taken to assure the best investment.
The U.S. has not enacted a wide-reaching, industrial energy efficiency bill since 1992 when the Energy Efficiency Policy Act was passed. This mandated that most general-purpose AC induction motors of 1 through 200 horsepower were required to be built to energy efficient levels per NEMA MG 1, Table 12-11 as of October 1997.
Latest Motors Articles
Electric motors have had a huge impact on the pump industry.
Improved motor starters help Fabri-Kal achieve its green vision.
The industrial motor world has a new specification available for defining the requirements of general purpose, severe duty motors in the 250- to 3,000-hp range.
Proper alignment of the pump shaft with the driver can reduce vibration and significantly improve reliability. For appropriate applications, the time, expertise and instruments needed to achieve precision alignment (tolerances of less than 0.005 in) will prevent seal leakage and extend bearing life.
Introduced in June 2010, Super-E Motors with AEGIS Shaft Grounding Ring are used in commercial and industrial applications to drive pumps provides a path to ground for circulating currents, preventing bearing fluting.
A paper or an electronic work order system can be used to capture alignment data.
Last September, we spoke about the importance of pipe-to-piping alignment, evaluating actual numbers, and tabulating stress values as they approach yield stress of pipe at various values of misalignment. This time, we will discuss the effects of pump-to-motor misalignment, beyond hype or generalities, by numerically quantifying the conclusions.
A number of choices are available when connecting pumps, fans and other rotating equipment to an electric motor. There are numerous mechanical and fluid coupling designs and, in some cases, a belt drive option is available. Although a belt drive can be more forgiving, all mechanical couplings share the requirement for precise alignment. Since couplings provide a direct physical connection between the motor and the rotating machine, misalignment will create vibration and other stresses that can lead to premature coupling, seal and bearing failure. Misalignment can be due to poor alignment practices or suction and discharge piping stresses.
Editor's Note: Click here to see a sample alignment data form.
Proper alignment of the pump shaft with the driver can reduce vibration and significantly improve reliability. For appropriate applications, the time, expertise and instruments needed to achieve precision alignment (tolerances of less than 0.005 in) will prevent seal leakage and extend bearing life.
Columns and Blogs
In this multi-part series, we will investigate several aspects of centrifugal pump efficiency.
First of Five Parts
Since the original publication of this draft standard in the January 2008 issue of Pumps & Systems, I have received feedback, encouragement, numerous questions and criticism. The draft listed three basic levels of repair.
The McGraw-Hill scientific dictionary [5] states that a volute is "a spiral casing for a centrifugal pump... designed so that speed will be converted to pressure."
