NEMA October 2009 ElectroIndustry - 18

electroindustry news individual IMs are defined, and TC 112 (Evaluation and qualification of electrical insulating materials and systems), which develops standards for the evaluation and qualification of insulating materials and systems. IMS member activities in these two international standards committees are consistent with the collective industry view that their experience is an essential ingredient and a part in any global effort to standardize IM testing, evaluation, and performance. As a consequence, the section has adopted the strategy that has its experts actively engaged in all technical discussions and work, at all levels, and, where possible, to assume a leadership role. For almost two decades, that strategy has translated into the successful pursuit of, and support for, a U.S. representative to oversee the key administrative tasks of TC 15 Secretary. This includes the publication of approximately 170 international standards that address the testing, evaluation, and performance of IMs that range from glass and ceramics to resins and varnishes, and include sleevings, papers and press boards, fi lms and laminates, mica materials, and tapes. The plethora of data these standards contain provides users with the assurances they need to select the materials that will meet the rigorous local, national, and international requirements for product performance, reliability, and safety. In addition to its support of the TC 15 Secretary, IMS members provide technical experts to participate in all of the active TC 15 and TC 112 working groups (WGs) and provide the chairman [convenor] for the critical WG 6 (Laminates). In pursuit of its strategy to be engaged in industry standards at all levels of development, and in all venues, and to seek leadership roles whenever possible and practical, IMS members have supported the recent appointment of one of their own as chair of IEC TC 112. That achievement fulfills the section objective to maintain its role in defining the technical criteria applied to electrical IMs in all necessary venues. The strategy ensures that NEMA members remain competitive in global markets requiring existing materials while being prepared to meet the challenges posed by emerging, new technologies. ei › Automatic Residential Controls and the Challenges for Smart Grid Smart Grid technologies open up possibilities for domestic appliances to optimize energy consumption through interactions with utilities while maintaining grid stability. The challenge for manufacturers and standards developers is to decide on a common communication scheme and to develop appropriate requirements to maintain required safety levels while integrating additional Smart Grid control function into the overall control system. One needs to ensure that communication data will not compromise safety functions under any mode of operation. Utilities want to distribute power efficiently. For household appliances, this means integrating demand reduction functions. For example, a utility could temporarily shut down an appliance that the homeowner has pre-arranged in exchange for a reduced energy bill. The challenge for manufacturers of automatic controls and appliances is to prevent any reduction in safety while permitting additional control function. IEC TC 72 has a long history in developing safety requirements for control devices. The need for these requirements is explained by its chairman Japp Dammer, who said, “A very important animal is IEC 60730-2-5, which concerns burner-control systems. Such a system is the heart of a gas- or oil-fired heating appliance.” Malfunction can lead to fire or explosion, making it the most potentially dangerous application in a home. Burner-control systems were among the first household applications equipped with safety-related soft ware. Electronic controls are now used in many different applications, such as laundry equipment, HVAC, lighting, and energy management. Because of the possibility of electromagnetic disturbances in the burnercontrol industry, it was necessary to introduce electromagnetic compatibility and immunity levels. Test levels had to be higher than in normal household appliances to account for the severity of the potential hazard. It was also necessary to specify possible failures or malfunctions of circuit components through risk or fault analyses. According to Rich Simons of Honeywell, at some point in a product’s life it will fail. “We are primarily concerned with the results of a failure. Controls must be classified as to the severity of the result of a failure.” For this reason TC 72 has classified controls based on the hazard a failure will create: • Class A: Not relied upon for safety, e.g., thermostat, lighting controls • Class B: Intended to prevent unsafe operation, e.g., thermal cut-outs and laundry door locks • Class C: Designed to prevent unsafe hazard, e.g., automatic burner controls and thermal cut-outs NEMA electroindustry • October 09

NEMA October 2009 ElectroIndustry

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