When maintaining motors, proactive strategies are required.
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Following the development of variable frequency converter drives during the 1990s, totally enclosed fan-cooled (TEFC) AC induction motors became viable options for replacing DC motors in pumping applications. The torque and speed characteristics of these motors are a close match to those required for centrifugal pumps.
I received many comments on my four-part series on AC Power, and most of them were very positive. Several readers, however, thought they were too elementary. I
reminded them that the title of my column is “Pump Ed101” not 201 or 301, and its purpose is to introduce people to new and unfamiliar topics. Why do I use this approach?
The pump industry is the largest purchaser of electric motors in the United States. According to the U.S. Department of Energy (DOE), electric motors consume more 50 percent of all electrical energy in the United States and more than 85 percent of industrial production electrical energy. Electric motors account for roughly $85 out of every $100 of a manufacturing/process plant's electrical bill.
Mechanically generated sparks, electrostatic discharge and high surface temperatures are all potential ignition sources in explosive atmospheres. Flexible couplings play a significant role in creating and/or eliminating these explosion hazards. Consequently, the European ATEX directive applies to couplings, and for good reason.
Water and wastewater systems in the United States use a tremendous amount of power. The EPA estimates that these systems use 50 trillion watt-hours annually at a cost of $4 billion. Combined with electric rate increases upward of 20 percent in a single year, water and wastewater system operators are left with an enormous strain on their budget.
Bigger Is Better-Or At Least It Used To Be
Owing partly to tradition, the shafts of electric motors are often larger than those of the equipment they drive. Engineers were very conservative a century ago when electric motors first came into widespread industrial use, so they typically designed in a sizable margin of error. Today's engineers haven't changed much in this respect. For example, standard NEMA frame dimensions, which have been revised only once since 1950, still specify much larger shaft sizes than commonly accepted principles of mechanical engineering would require.
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.
Aligning an electric motor coupled to a large air blower required multiple measurements.
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.
Latest Motors Articles
Electric motors have had a huge impact on the pump industry.
Improved motor starters help Fabri-Kal achieve its green vision.
How do I move from my situation to a better one? In other words, is it possible to retrofit a less-than-optimal installation with a better solution, and how?
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.
Shaft failures do not happen everyday, but when they do, it can be a challenge to determine the cause of failure. Here's a technical explanation of what happens when the shaft bends or breaks.
The frame sizes (physical dimensions) of AC motors have changed substantially through the years. Originally, they were considerably larger than those in use today. This increased size was the result of inefficiency and the need to dissipate heat.
Why and how do leading OEMs choose a variable speed motor for their equipment? While rated efficiency has been an important driver in the past and will continue to be one in the future, leading equipment and machinery manufacturers now use sophisticated variable speed technologies to radically redefine their products. pump efficiency
After spending money on a powerful new pump and the motor to run it, the next big decision is how to connect the two in a way that maximizes their efficiencies and protects them from normal wear and tear.
Why integrating vibration monitors with process controls provides fast response to pump faults, adds predictability and avoids unexpected shutdowns.
The low voltage motors market is highly consolidated, with the top five participants accounting for more than 75 percent of the market revenues as of 2009. Low voltage alternating current (AC) motors dominate the industry, generating 92.1 percent of market revenues for 2009. That number is expected to increase to 95.9 percent by 2016, with a Combined Annual Growth Rate (CAGR) of 7.6 percent between 2006 and 2016. Low voltage direct current (DC) motors, on the other hand, are expected to have a negative 3.4 percent CAGR between those years.
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The performance of a centrifugal pump with a trimmed impeller will follow the affinity laws as long as that trim is relatively small.
Standards for repair will begin with a standard for vertical turbine pumps.The pump industry is undergoing renewed interest in the technical aspects and quality of repairs.
Charlie Jackson was unaware of any centrifugal pump manufacturer that knew how to calculate hydraulic axial thrust produced within liquid ends of their pumps.
