Letters: Reader Feedback

Power for security In the article “Quality Power for Security Systems” (Pure Power, Fall 2007, p. 17) the author gives “underground local metal structures (gas piping, for example)” as one of the legal ways of connecting a grounding system to the earth. The author refers to the National Electrical Code for the listing.


Power for security

In the article “Quality Power for Security Systems” (Pure Power, Fall 2007, p. 17) the author gives “underground local metal structures (gas piping, for example)” as one of the legal ways of connecting a grounding system to the earth. The author refers to the National Electrical Code for the listing. But according to NEC Article 250-52(a), “a metal underground gas piping shall not be used as a grounding electrode.” Can the author expand on this?

Igor A. Altshuler Engineer Baltimore via the internet

Author responds:

Indeed, you are most correct. The statement should have read “Other local metal underground piping (except gas lines).” Likewise, tanks that have been used to store explosive or hazardous contents should not be used as supplemental grounding electrodes. An acceptable example would be an abandoned underground metallic water storage tank that has been filled with moist sand.

Jay Adams Applications Engineer Transtector Systems Shayden, Idaho

Energy efficiency

The story “The climate has changed for energy efficiency” ( www.csemag.com , 10/22/07) said that “the energy used by commercial and industrial buildings in the United States is responsible for 45% of the nation's greenhouse gas emissions.” This is encouraging for the potential to make a big dent in those emissions. Although most domestic and non-domestic buildings are very wasteful of energy, in many ways that waste is easier to tackle in non-domestic buildings: First, the energy bill is usually much higher in non-domestic buildings, so there are greater financial rewards to be achieved by investing time into improving energy efficiency. There's a big economy-of-scale effect in the savings that can be achieved by investing time into energy management.

Second, the larger the building, the greater the chance that it already has interval metering equipment and access to interval energy data from that equipment. For buildings that don't have such equipment, the larger they are, the greater the payback from investing in such equipment. Analysis of such interval energy data for energy management purposes can easily lead to identification of huge sources of energy waste that would be very difficult to find without that data. Admittedly, these benefits will spread into the domestic sector as interval metering catches on there. Ultimately, the greatest energy saving are from motivating people to do their bit. This can be difficult in a work or home environment, but initiatives such as the Kilowatt Crackdown can make a huge difference.

Martin Bromley Energy Management Consultant via the internet

No comments
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by...
Each year, a panel of Control Engineering editors and industry expert judges select the System Integrator of the Year Award winners.
Control Engineering Leaders Under 40 identifies and gives recognition to young engineers who...
Learn more about methods used to ensure that the integration between the safety system and the process control...
Adding industrial toughness and reliability to Ethernet eGuide
Technological advances like multiple-in-multiple-out (MIMO) transmitting and receiving
Virtualization advice: 4 ways splitting servers can help manufacturing; Efficient motion controls; Fill the brain drain; Learn from the HART Plant of the Year
Two sides to process safety: Combining human and technical factors in your program; Preparing HMI graphics for migrations; Mechatronics and safety; Engineers' Choice Awards
Detecting security breaches: Forensic invenstigations depend on knowing your networks inside and out; Wireless workers; Opening robotic control; Product exclusive: Robust encoders
The Ask Control Engineering blog covers all aspects of automation, including motors, drives, sensors, motion control, machine control, and embedded systems.
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
News and comments from Control Engineering process industries editor, Peter Welander.
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
This is a blog from the trenches – written by engineers who are implementing and upgrading control systems every day across every industry.
Anthony Baker is a fictitious aggregation of experts from Callisto Integration, providing manufacturing consulting and systems integration.
Integrator Guide

Integrator Guide

Search the online Automation Integrator Guide

Create New Listing

Visit the System Integrators page to view past winners of Control Engineering's System Integrator of the Year Award and learn how to enter the competition. You will also find more information on system integrators and Control System Integrators Association.

Case Study Database

Case Study Database

Get more exposure for your case study by uploading it to the Control Engineering case study database, where end-users can identify relevant solutions and explore what the experts are doing to effectively implement a variety of technology and productivity related projects.

These case studies provide examples of how knowledgeable solution providers have used technology, processes and people to create effective and successful implementations in real-world situations. Case studies can be completed by filling out a simple online form where you can outline the project title, abstract, and full story in 1500 words or less; upload photos, videos and a logo.

Click here to visit the Case Study Database and upload your case study.