Gail Leach Carvelli
A new 20-minute educational video from Fluke Corp. (Everett, WA) provides insight into handling a number of electrical-power disturbances such as sags, swells, and overvoltages and undervoltages. Managing Electrical Power Systems also addresses the increasing problems associated with nonlinear electrical loads that lead to higher-than-normal frequencies, or harmonics.
Harmonics can be found wherever there are large numbers of personal computers, adjustable-speed drives and other types of equipment that draw current in short, abrupt pulses, instead of in a smooth sinusoidal manner, says Dick Troberg, senior product specialist with Fluke.
"Our high-tech buildings are full of harmonics because of the proximity of the cable systems to the power systems. And the problems are getting steadily worse because more and more people are buying energy-efficient products," explains Troberg. He adds that use of energy-efficient equipment combined with the emergence of low-cost power semiconductors produces harmonic currents, which can overheat transformers and neutrals, and trip circuit breakers.
The complexity of these problems and their increasing occurrence led the company to research harmonics in depth. "Several years ago, we realized that some customers were having problems with harmonics in their electrical systems," says Debby Coyne, product publicity manager. "We felt they were important problems to address and began researching the subject. And we knew we wanted to get this information out to the electrical community."
Consequently, Fluke produced two videos, Understanding Harmonics and Managing Harmonics. Troberg says Understanding Harmonics presents the basic concepts and theories behind harmonics and explains their physical effects and common troubleshooting techniques. Managing Harmonics provides ways to track harmonics and their sources and offers useful mechanisms for managing these problems.
Managing Electrical Power Systems takes a broader approach to power-quality issues, supplying an overview of power disturbances and providing a basic understanding of power quality and energy-management systems. The video also discusses ways to manage power-factor correction and reduce overall energy costs.
The video does all this by targeting power-management problems found in four common locations: adjustable-speed drives, induction motors, receptacle load centers and lighting load centers. Solutions are offered that use the company`s line of power meters.
Managing Electrical Power Systems comes with the purchase of either a Fluke 39 Power Harmonics Meter or a Fluke 41B Power Harmonics Analyzer. This video, along with Understanding Harmonics and Managing Harmonics, can be ordered by calling (800) 526-4731. Each video costs $19.95.