Though not known as one who dwells in the past or the "good ol' days" mentality, this column happens to mark the silver anniversary of my contributions to Electrical Contractor. It also comes on the heels of a recent meeting with the editor and associate editors to discuss ways to better serve the readership. While it was a great meeting with those who work diligently to help make what sometimes can be geek-speak into polished prose each month, this might be an opportunity to open it up to the readership at large for additional topics that would be of interest to them in the power quality, energy and demand fields.
Over the years, I have covered topics ranging from the most common type of power quality phenomena (sags, swells, interruptions, harmonics, interharmonics, transients, unbalance and flicker to name a few) to how to conduct a power quality audit. Ohm's and Kirchoff's Laws seem to creep into the discussion every few articles, as they serve the basis for analyzing what is happening in the electrical world. We have followed the path of the electrons from generation by the electric utilities through the transmission and distribution systems, past the service entrance (or point of common coupling) and into the facility, where various types of loads can alter the sine wave of both the voltage and the current.
With oil above $100 per barrel, people are starting to look again into energy efficiency and how to reduce their electricity bills. That requires an understanding of just where the power demand, energy consumption and power factor charges come from, which requires those pesky two laws again. Most facilities have opportunities to significantly reduce their electrical bills from 10-20 percent with a relatively short payback period, while helping to simultaneously green the environment.
How the electricity is used in a facility and what can go wrong has often been a topic, ranging from transformers to adjustable speed drives to surge protectors. It seems that one of the readership's favorite articles was the one on the effect of a lightning strike at a residential dwelling (which was actually written by my son, Scott, whom I no longer allow to write articles after finding out that even the Electrical Contractor staff agrees with the readers). How to minimize the effect of power quality disturbances from affecting the equipment is a logical follow-on to how those disturbances are created, and often, a piece of equipment can be both the source and victim of such. Backup generators, uninterruptible power supplies, transient voltage surge suppressors, harmonic filters and improved grounding are a few of those discussed in the past.
The goings-on in the standards-making groups appear periodically, as I serve on such committees as the NFPA 70B Electrical Equipment Maintenance, National Electrical Code (NEC, NFPA 70) and numerous IEEE committees. Though most of those documents are "recommended practices" (except the NEC, of course), they are very useful documents for electrical contractors to either have in their possession, to refer to on a regular basis or at least to be familiar with how they can affect daily tasks. Paramount among these also is the NFPA 70E, covering an electrically safe workplace. There still are far too many injuries and deaths from electricity each year, and we all need to work toward reducing these senseless numbers.
Knowing the difference between a wye and delta circuit is as important for how it can affect the quality of the power in a facility as it is to getting the proper power readings when connecting meters and monitoring instruments. The computer adage "garbage in-garbage out" applies to using a sophisticated power quality monitor with the voltage leads and current probes improperly connected.
With so many electronic loads in a facility connected through communication circuits, such as 10baseT Ethernet LANs, the complexity of troubleshooting problems in a facility continues to grow. Attending National Joint Apprenticeship and Training Committee and other training courses is critical to stay abreast of what is happening in the field and where there is money to be made, even during a downturn in residential construction. Likewise, Electrical Contractor is a great place to read up on changes in the latest revision of the NEC.
So, I thank you all for your continued interest in the column, and encourage you to send your ideas to the editors or call me about a topic in which you would like more insight.
BINGHAM, a contributing editor for power quality, can be reached at 732.287.3680.