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Author: Ken Gettman

What are the driving forces behind expansion of LVDC beyond Data Center Applications?

What are the driving forces behind expansion of LVDC beyond Data Center Applications?

The ability to directly link between photovoltaics or energy storage mechanisms and direct current (DC) rated utilization equipment is an attractive option to avoid the potential energy losses and heat generation associated with power conversion from DC-to-AC-to-DC.  Many pieces of utilization equipment, particularly IT, home electronics and appliances, and office equipment are actually operated by DC supplied from individual power supplies that convert the AC current from the utility or building Read more [...]
Impact of EMF Exposure Limits and MRI

Impact of EMF Exposure Limits and MRI

Articles, by Professor J.C. Lin of the University of Illinois in Chicago, highlighting ICNIRP’s role in establishing limits for EMF exposure during MRI procedures were published in IEEE periodicals Microwave Magazine, vol. 12, no. 4, pp. 46-56, June 2011, and in Antennas and Propagation Magazine, vol. 53, no. 1, pp. 169-174, Feb.2011.  The articles provide useful information but do not tell the whole story regarding low frequency exposure limits, specifically recognition of the work of Read more [...]
LVDC – Wave of the future or Technogimic?

LVDC – Wave of the future or Technogimic?

Lately, a return to using low voltage DC power, at least in some applications, had gotten a lot of attention.  There was a US workshop sponsored by NEMA, UL and NFPA that drew over 140 participants.  A workshop was recently held in Europe that had over 70 attendees.  Demonstration installations for data centers and community level distribution have been constructed and tested.  A consortium, EMerge Alliance, has developed a standard and applications for using LVDC for office lighting Read more [...]
Does China Deserve to be an IEC Group A member?

Does China Deserve to be an IEC Group A member?

In the world of the International Electrotechnical Commission (IEC) there are several categories of membership for the countries that participate in that international standards body.  Full members are those National Committees that have access to all technical and managerial activities and functions, at all levels of the IEC, including voting rights in the IEC Council.  There are also Associate members and affiliate members.  Within the Full Member category, there is an additional Read more [...]
Are Cellphones really dangerous?

Are Cellphones really dangerous?

The declaration from International Agency for Research on Cancer that cellphone emissions are possibly carcinogenic is not only old "news" but it is not scientifically substantiated.  The conclusion IARC reached was based on a review of a set of published articles evaluating the effects of electromagnetic emissions on biological cells or animals.  Their classification would put cellphones in the category that includes the pesticide DDT and gasoline engine exhaust, and even caffine Read more [...]
LVDC and Harmonic Currents

LVDC and Harmonic Currents

NEMA, UL and NFPA sponsored a very successful workshop in Crystal City, VA during April on the topic of Low-Voltage Direct Current.  There were 17 presenters and over 140 attendees at this state-of-the-industry event.  LVDC is of interest because establishing a direct connection between distributed power generators (especially photovoltaics) plus energy storage devices (mostly batteries) and the many electronic products that operate on LVDC allows elminiation of Read more [...]
What will it take?

What will it take?

Standards developed under the umbrella of the International Electrotechnical Commission (IEC) facilitate international trade and enable manufacturers to maintain a single product for world market access.  Many governments adopt IEC standards as their own and may even include them in their regulatory structure to help ensure the safety of their country's populace and property on the basis that compliance with the requirements establishes playing field on which producers must compete Read more [...]
Why Doesn’t Europe Want the Best Fire Protection

Why Doesn’t Europe Want the Best Fire Protection

Fire pump controllers, assemblies of electronic and electrical devices, are intended to ensure critical life-safety operation of fire-fighting pump motors in buildings.  If the pump motors or the controllers fail to operate, there is significant potential for loss of life and loss of buildings and their contents.  Why would anyone write a regulation that could hamper the ability to provide protection against fire? There is a need for electrical current protection Read more [...]
RESEARCHERS MISLEADING PUBLIC ON RISKS OF EMF

RESEARCHERS MISLEADING PUBLIC ON RISKS OF EMF

In a statement issued on 2 June 2010, the Institution of Engineering and Technology (IET) has released an updated position statement concluding overall that "the balance of scientific evidence to date still does not indicate that harmful effects occur in humans due to low-level exposure to EMFs."  EMF stands for Electric and Magnetic Fields, which are, as described by the National Institute of Environmental Health Sciences (NIEHS), “invisible lines of force associated with the Read more [...]
Does Canada Need Harmonics Emissions Limits?

Does Canada Need Harmonics Emissions Limits?

The Canadian Standards Association has been pursuing adoption of IEC 61000-3-2: Electromagnetic compatibility (EMC) - Part 3-2 and 61000-3-12: Electromagnetic compatibility (EMC) - Part 3-12 that provide requirements on limiting device harmonic current emissions.  These documents, and IEEE 519, provide requirements for limiting the effect of various products on power quality due to the way they process power for their operation.  However, why are these documents Read more [...]