Power Shift
Oct 1, 2008, By Chuck Heller, Chloride North America
Responding to market needs, server technology has rapidly advanced, delivering high-density, highly reliable computing without the massive harmonics issues...
The Case of Overheated Transformers and Neutral Conductors
Sep 1, 2008, By Steven L. Pay, P.E., L.C., LEED AP, Finnegan Erickson Associates
Historically, typical loads of commercial power systems have been predominately linear; however, in the last few decades, a significant portion of these...
Learning to Read Waveform Signatures
Sep 1, 2008, By Mark McGranaghan, EPRI Solutions
Today, many facilities have online monitoring systems that continuously track power quality, provide valuable information about energy use, and characterize...
The How's and Why's of IG Wiring
Aug 1, 2008, By Thomas M. Gruzs, Emerson Network Power
It's hard to buy a new electrical device these days that doesn't contain electronics....
Verifying Ground-Fault Coordination for MV Power Cable Shielding
Aug 1, 2008, By John DeDad, Senior Director, Editorial and EC&M Development
According to the IEEE Buff Book, "A power cable must be protected from overheating due to excessive short-circuit current flowing in its conductor," which may damage or destroy the insulation....
Can Your SPD Go to Extremes?
Jul 1, 2008, By Carey Mossop and Alan Chiste, Eaton Corp.
Surge protective devices (SPDs) have become an integral part of residential, commercial, and industrial power quality applications. The best SPDs provide...
The Case of the Unreliable Conveyors
Jul 1, 2008, Edited by John DeDad, Senior Director, Editorial and EC&M Development
In certain instances, system operation problems can be cyclical, many times correlating with utility or facility power system operation. Other times,...
Powering Change in the Data Center
Jun 1, 2008, By Russell Shetler, Emerson Network Power
Changes in the quantity, configuration, and density of servers are reshaping the data center environment these days....
UL 1449 and the 2008 NEC
Jun 1, 2008, By Joseph DeGregoria, Underwriters Laboratories
The use of surge protective devices (SPDs) within residential, commercial, and industrial applications has sharply increased over the last decade...
Surge Strips vs. Plug-in Power Conditioners
May 1, 2008, By Andy Goldin, Powervar
If you've ever wondered how surge protector strips are different from plug-in power conditioners, you're not alone. The enormous difference in price makes...
Understanding Harmonic Indices
Apr 1, 2008, By John DeDad, Senior Director; Editorial and EC&M Development
The power quality industry has developed certain index values that help us assess the quality of service as it relates to distortion caused by the presence...
Simplifying the Search for Unwanted Ground Current
Apr 1, 2008, By Tom Shaughnessy, PowerCET
Ground fault circuit breaker problems look simple on the surface: Too much current and bang, breakers trip. And when they trip, everyone pays attention....
Crest Factor: A Key Troubleshooting Parameter
Mar 1, 2008, John DeDad ,, Senior Director, Editorial and EC&M Development
We all know that electric utilities in the United States generate electricity at various 60-Hz voltage levels that result in a sine wave waveform. The...
Focus on Power Quality Devices
Mar 1, 2008,
Surge protector Strikesorb surge protection devices (SPDs) meet the requirements of the international IEC 61643-1 standard as well as the 2007 UL-1449...
Protecting Critical Loads with Commodity UPSs
Mar 1, 2008, John DeDad ,, Senior Director, Editorial and EC&M Development
The need for small commodity UPS systems has grown significantly in recent years because of the increase in telecommuting, home offices, and distributed...
UPS Testing for Reliable Backup Power
Feb 1, 2008, By Joseph Ong, Fluke Corp.
No electricity provider in the world can guarantee an electrical supply that is free from voltage and frequency variations. The possibility of faults...
Power Quality Considerations for Security Systems
Feb 1, 2008, By Jay Adams, Transtector, A Smiths Business
Reliable operation of security systems is obviously essential to protect company assets and ensure human safety. However, episodic equipment malfunctions...
Tracking Down Transient Voltages
Jan 1, 2008, By Tom Shaughnessy, PowerCET
Have you just spent another day at the office fighting with computers? Join the club. Besides viruses, malware, and software, is it possible that something...
The Pros and Cons of IG Wiring
Nov 1, 2007, Edited by John DeDad, senior director, editorial and EC&M development
Confusion continues to surround the use, performance, and NEC requirements of isolated ground (IG) wiring. Can it be used anywhere, or is it restricted...
Observations on Supplemental Grounding and Bonding: Part 3
Sep 1, 2007, By William Bush, Panduit
In Part 2 of this article (August 2007), we described multipoint (or common-type) supplemental grounding and bonding between the T(M)GB [notation used...
