Consider more than the efficiency rating to select the most cost-effective system for the pumping application.
Power factor (PF) is an important component of an alternating current (AC) circuit, but understanding its actual effect can be difficult. Why is PF mysterious to many of us? It has to do with the way...
I hope that my last column (Pumps & Systems, September 2014) provided a clearer definition of power factor and how it can be calculated. Power factor can also be explained using a vector triangle, but...
The economic downturn has delivered a heavy blow to the industrial manufacturing sector in North America. Manufacturers are indicating sales drops of 30 percent to nearly 60 percent compared to that...
As a follow up on my AC Motors series, I thought it would be a good idea to provide a short overview of work, power and torque as it applies to the AC motor. I will provide a reference to a more in...
As a follow up on my AC Motors series, I thought it would be a good idea to provide a short overview of work, power and torque as it applies to the AC motor. I will provide a reference to a more in...
AC Motors Part 3-Single Phase Operation
It has been said that Washington, D.C., is the home of the largest invertebrate population in the U.S. This, of course, jokingly refers to the population of politicians and their lack of backbone or...
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...
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...
AC Motors Part 5: AC Motor Life
One of the major impacts on motor life is common sense—or maybe the lack thereof!It always amazes me how many open drip proof (ODP) motors are used in agricultural irrigation applications where...
AC Motors Part Two-Three Phase Operation
Although a number of AC motor designs are used, the induction motor is, by far, the most common and will be the topic of this column. We will also focus on the three-phase design as it provides a more...
AC Motors: Magnetism and the DC Motor
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. Ireminded them that the title of my column...
AC Power (Part Four): Transformers
Last of four partsLast month, we studied the properties and effects of resistive, inductive and capacitive loads in an AC circuit. This month, we will take self induction a step further and apply it...
AC Power (Part Three): AC Circuit Loads
AC Circuit LoadsLast month we discussed the relationship between voltage and frequency and tried to make that somewhat complex three phase sine wave a bit more understandable. This month we will...
AC Power Part 1: AC Versus DC
First of Three PartsThis three part primer is a basic introduction to AC power for those in the pump industry who need a place to start. It will also provide several web references to access if you...
AC Power Part Two: Voltage Versus Frequency and the Three Phase Curve
Last month, we ended with a discussion of the relationship between peak and RMS (or effective) voltage. We found that the RMS voltage will always be 0.707 that of peak voltage, and peak voltage will...
Additional equipment and built-in technology move these drives into new applications.
Alignment Tolerances
The biggest decision is determining which tolerances to align. In the alignment training classes that we teach, questions arise about alignment tolerances. We often ask, “What are your...
Baldor Electric Company hosted its Fundamentals of Motors class, Dec. 1-3, to educate industry veterans and novices alike on everything motor-related, from basic parts and components to calculating...
In plants that process combustible materials, these motors avoid electrical damage often caused by energy-saving inverters.
Calculating Energy Savings and Payback
Energy efficiency and reduced consumption are important issues in the pump and motor marketplace. Over the long term, electricity costs will continue to increase regardless of our actions. This will...
Pumps & Systems, October 2007Back in the early seventies, when I was in grad school, our government pledged to convert the U.S. measurement system to the metric system. A popular cartoon at the...
Back in the early seventies, when I was in grad school, our government pledged to convert the U.S. measurement system to the metric system. A popular cartoon at the time showed a lab technician with a...
A VFD and a permanent magnet, direct-drive motor replace a gearbox, reduce maintenance costs and provide energy savings.
Coupling Considerations for Pump Applications
A flexible coupling's primary functions are connecting two shafts, transmitting power from a driver shaft to a driven shaft and accommodating the misalignment between them. With only these...
Pump and Systems, June 2009 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...