Don't Let Sags and Interruptions Disturb You
Aug 1, 1998, By Larry Ray, Square D
Voltage sags and interruptions can be costly forms of power quality disturbance. But using waveform capture information can help you find which event is causing the shutdowns....
Harmonic Distortion: Definitions And Countermeasures—Part 3
Jul 1, 1998, By Cory J. Lemerande, Magnetek
You know you have harmonics, because you've seen the graphical display on your harmonics analyzer. The big question is: "How do I get rid of them?" The answers lie not in magic, but in applying fundamental principles and possibly a few specialized cures....
Harmonic Distortion: Definitions And Countermeasures, Part 2
May 1, 1998, Cory J. Lemerande
Resolving harmonic problems is easier than some people would have you think. If you understand some basics, you'll be able to eliminate most of the mystery.In...
Quick Checkpoints To Prevent Lightning-induced Damage
May 1, 1998, Ken Michaels
Be sure to make an annual visual inspection of your facility and check connections throughout the grounding system. And, don't forget to take bonding...
Harmonic Distortion: Definitions And Countermeasures
Mar 1, 1998, Cory J. Lemerande
While harmonics are important, they need to fit into the larger context of power quality. While you must consider harmonics, they are not the demon some...
A Balanced Way To Look At Power
Feb 1, 1998, Mark Lamendola
Balance is so important. We have balanced meals, balanced checkbooks, and balanced tires. We pride ourselves on laying out distribution panels such that...
Engine Gen-Sets: Investing In Power Reliability
Feb 1, 1998, Staff
New Jersey-New York City bridge uses packaged twin 400kW engine-generators to keep toll booths and roadway lighting operating.How do you keep the revenue...
Beware Of Line-Current Unbalance On VFDs
Jan 1, 1998, John A. DeDad
Severe line-current unbalance can cause VFD nuisance tripping and 3rd harmonic currents, which are unusual for phase-to-phase nonlinear loads.Are you...
Power Factor Correction On Single Induction Motors
Jan 1, 1998, Ed Cowern
Sometimes, you need to correct power factor (PF) at a single motor. This means sizing PF capacitors for that motor. The good news is if you size your...
Meeting IEEE 519 THD Limitations: A Case Study
Dec 1, 1997, Marina Dishel, P.E. and John R. Nasto, P.E.
Don't place a variable frequency drive (VFD) on a circuit until you determine the nature and magnitude of harmonics the drive may pump back into the feeding...
The how, what, and where of power conditioning. (part 7)
Dec 1, 1996, Waggoner, Ray
New MV products can transfer in milliseconds while others sense sags and boost voltages quickly.Although we usually don't associate the term "power quality"...
Power conditioning and protection
Nov 1, 1996,
Manufacturers provide a wide array of answers to power quality questions. Some of these answers are whole new technologies, while others are reincarnations...
The how, what, and where of power conditioning. (part 6)
Nov 1, 1996, Waggoner, Ray
Solid-state subcycle switching devices can eliminate the need for a UPS, if two sources of power are available.For more than 70 years, we've had the motor-generator...
The how, what, and where of power conditioning
Oct 1, 1996, Waggoner, Ray
Depending on the sensitivity of the load and its critically, differing configurations of solid-state UPS systems can do the job.In last month's session,...
Why poor power quality causes electronics failures.
Sep 1, 1996,
Why does a two-cycle power outage create havoc with electronic equipment when, sometimes, a three-cycle outage causes no problems?We seem to know so little...
