It has been said that Washington, D.C., is the home of the largest invertebrate population in the U.S.
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.
One of the major impacts on motor life is common sense—or maybe the lack thereof!
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.
Last month, we studied the properties and effects of resistive, inductive and capacitive loads in an AC circuit.
This month we will quickly look at the load types that comprise a typical AC circuit.
This 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 would like to further your understanding of this interesting and essential topic.
Last month, we ended with a discussion of the relationship between peak and RMS (or effective) voltage.
Back in the old days, level control had little or nothing to do with saving energy. In fact, it was often a necessary evil. Today, that is no longer true - the VFD offers the potential for power savings in lift station applications that range from a few hundred gallons per minute to those that have to move thousands of gallons each minute.
Energy efficiency and reduced consumption are important issues in the pump and motor marketplace.
Starting can have a significant effect on the life of the winding insulation of an AC motor.
Curve shapes reveal a pump's range of peak efficiency.
The performance of a centrifugal pump with a trimmed impeller will follow the affinity laws as long as that trim is relatively small.
Early centrifugal pump design was heavily influenced by turbine technology during the mid to late 1800s.
In this multi-part series, we will investigate several aspects of centrifugal pump efficiency. First of Five Parts
Factors to consider when deciding the priority of pump efficiency.
You have probably noticed that there are several camps out there when it comes to centrifugal pump applications involving variable frequency drives (VFDs). One group believes that every pump should have one, while another thinks that they should be banned altogether. And, of course, there is the middle ground that says it depends upon the pump and application. pump system optimization, pump efficiency
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 box of amputated human feet standing at the door of the supply room. The supply clerk was also holding a box, but his was full of volt meters. The caption was "Trading Feet for Meters." That was almost 37 years ago, and we still have most of those feet! I guess that I could say that we are still "inching" into the metric system.
The SI system is the modern day version of the metric system, and the U.S. gets a lot of grief for not embracing its inherent transportability across international boundaries.
Have you ever wondered why a motor manufacturer would state that many of their 60-Hz motors will operate on 50-Hz power as long as you reduce the nameplate voltage by 1/6?