Threat of Litigation Causes Consultants to Decline Work
Nov 1, 1998, By EC&M Staff
The threat of litigation and frivolous lawsuits continue to be a primary concern for consulting engineering firms, according to the 1997-1998 Professional...
Industry Experts Question EMF Working Group Report
Oct 1, 1998, By EC&M Staff
A working group, put together by the National Institute of Environmental Health Sciences (NIEHS), judged (by a vote of 19 to 9) that the International...
Data And Power Wiring: Similarities & Differences
Oct 1, 1998, By Paul Rosenberg, Consulting Editor
The industry is instinctually familiar with power wiring. Now, it's time for electrical contractors to learn as much about data wiring as they already know about power wiring....
Some Motors Have Design B LR Limits But Meet Design E Efficiency Levels
Oct 1, 1998, By EC&M Staff
Thanks for Robert Lawrie’s article, “Watch Out For Burnouts On Hard-To-Start Loads,” in the March issue. With continuous change and increased efficiency,...
Diodes or SCRs? It's Either Or
Oct 1, 1998, By EC&M Staff
While reading Cory Lamerande’s article on harmonic distortion (March issue), I found a contradiction. The text under Figure 5, on page 74, (reproduced...
What’s the Most Cost-Effective Way to Obtain 380V?
Oct 1, 1998, Edited by Robert J. Lawrie
Q. A large textile plant purchased several looms from Europe, which operate on 380V, 3-phase. The only distribution voltage available is 480V, 3-phase....
Quick Disconnects Speed Motor Changeouts
Jul 1, 1998, By Jerry Woodward, Thomas & Betts Corp.
Unique device has contact rings with high conductivity and high contact force....
Backup Your Backup
Jun 1, 1998, By Paul E. Pritzker
Providing protection for critical loads without also providing UPS protection simply transfers the risk form one component of a system to another....
Turning The Tables On Shaft Voltage And Bearing Currents
Jun 1, 1998, By David W. Schlegel, Russel J. Kerkman, and Gary L. Skibinski
High bearing current concentrations can damage bearing raceways. This damage can degrade bearing performance and even shorten motor life....
Motor And Drive Compatibility: A Must
Jun 1, 1998, By Paul K. Lindhorst, Magnetek
You bought VFDs to improve operations and processes while saving energy. Yet, you're seeing many costs going up and motor failures doubling. What's happening? It's almost certain you have a mismatch between your drives and motors. However, such a mismatch doesn't have to be....
Reduced-Voltage Starters: Choosing The Best Type For Your Application
Jun 1, 1998, By Steven N. Hinman, P.E.
The power company requires reduced-voltage starting to limit its line voltage dip. What type of starter is best for various-sized motors ranging from 200 hp to 2000 hp? See how a comparison of autotransformer and solid-state technologies drives the decision process....
Through-Wiring with Recessed Fixtures
Jun 1, 1998, By Michael O'Boyle, Lightolier
You may be surprised at how many conductors can pass through many fixture wiring compartments without requiring identification for through-wiring suitability....
Maybe You Should Choose A Brushless DC Motor
May 1, 1998, Terry Auchstetter
Brushless DC motors offer definite advantages in certain applications. So, should you automatically choose a brushless DC? After all, you're familiar...
Design/Build Job Saves High-rise Owners Money
Apr 1, 1998, Joseph R. Knisley
When Cleveland Electric, Atlanta, was hired on a design/build basis as the installing contractor for the renovation project of the William Oliver Building,...
Design/Build: Hard Facts About Software
Apr 1, 1998, John Chaney and Mark Lamendola
Does the new era of design/build mea you need a massive library of software to stay competitive? Some people say yes. The truth? All you need is a handful...
Uninterruptible Power Supplies: Distributed vs Centralized?
Mar 1, 1998, Shawn Smith
If you base your answer to this question on a thorough analysis, you could avoid a major blunder as well as unplanned equipment downtime.Which is a better...
Protecting Generators From Overload
Feb 1, 1998, Lawrence Bey
Pay close attention to how you size overload protection for generators. Now there's new technology that lets you better coordinate that protection with...
Using Interlocked-Breakers For Maintainable Automatic Power Transfer
Jan 1, 1998, James D. Martin
Space limitations forced a design-build company to use a novel approach to critical load transfer without interruption. Continuous facility operation...
When Is A Circuit Breaker Not A Circuit Breaker?
Jan 1, 1998, John W. Young and Ray Clark
Not all resettable overcurrent protective devices are circuit breakers; some are supplementary protectors. So how do you know one from the other?When...
Clearing The Mystery Of Protective Relays
Jan 1, 1998, John A. DeDad
MV system coordination doesn't have to be complicated, as long as you know the types of protective relays available, their function, and how they work.Recently,...
