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.
This month we will quickly look at the load types that comprise a typical AC circuit.
I received many comments on my four-part series on AC Power, and most of them were very positive.
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.
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.
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.
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.
Aligning an electric motor coupled to a large air blower required multiple measurements.
All electric motors (motors) have a housing that contains the working components of the motor.
Water and wastewater systems in the United States use a tremendous amount of power.
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.
Advanced motor protective relays provide superior protection for motors and pumps. pump system optimization
Last month, we ended with a discussion of the relationship between peak and RMS (or effective) voltage.