The IEC Advisory Committee on EMC (ACEC): Coordination of International EMC Standards

Since its formation, ACEC has developed a unique structure for EMC publications that is used to this day in the IEC and in other regional standardization organizations.

While many EMC engineers are familiar with the electromagnetic compatibility (EMC) standards developed by the International Electrotechnical Commission (IEC), they are probably unaware of how the structure of the IEC EMC standards effort was developed over the years or how this structure is maintained. The IEC has over 175 committees and subcommittees dealing with electrical and electronic products and systems. These product committees must deal with “horizontal” aspects such as safety, environmental protection, and EMC—in addition to those factors that directly involve the performance of their products of interest. For this reason, the EMC committees within the IEC (namely CISPR and TC 77) develop the basic standards that can be applied by the product committees. The hierarchy of IEC EMC standards and the ways to write EMC standards within the IEC were developed by and are maintained by the Advisory Committee on Electromagnetic Compatibility (ACEC).

This paper reviews the early history of ACEC, the current status of ACEC, and IEC Guide 107 (written by ACEC) that implements the EMC strategy within the IEC. Also, a summary of important accomplishments of ACEC over the past decade is provided along with emerging issues likely to demand future consideration.

BRIEF HISTORY OF ACEC

On 21 June 1978, the Committee of Action (the technical management board of the IEC at the time) set up an EMC Coordinating Working Group (EMC-CWG), whose task was to coordinate the IEC work dealing with EMC and to advise the Committee of Action if there were problems in the manner in which the EMC standards were being applied. After an organizational period, the first meeting of the EMC-CWG was held on 12–13 March 1980 in Geneva, Switzerland. The first Chairman of the EMC-CWG was Prof. Ralph Showers (U.S.) and the Secretary was Mr. A. Foulkes. Prof. Showers served as Chairman of the EMC-CWG from 1980 to 1991; the name of the committee was changed during this period to ACEC.^[1]

Mr. Georges Goldberg (Switzerland) was elected as the next chairman and served from 1992 until 1996. Mrs. Margaret Read served as Secretary during most of this period. The next ACEC Chairman was Dr. William Radasky (U.S.), who began his term on 1 January 1997 and will serve until the end of 2008. Secretaries over this period included Mr. Gabriel Barta from 1997 to 2001 and Dr. Rémy Baillif from 2002 to the present.

ACEC TODAY

While the names of committees and boards within the IEC have changed over the years, the role of ACEC has stayed the same. ACEC reviews the development of basic EMC standards produced by CISPR and TC 77 and the way these standards are applied by product committees of the IEC. Additionally, ACEC coordinates with ISO, ITU, and other international and regional standards bodies to ensure that the EMC work in the international community is performed in a consistent manner. In all cases, ACEC recommendations for action are submitted to the successor of the Committee of Action, which is now known as the Standardization Management Board (SMB), for its approval. This Board makes the technical decisions regarding IEC standards development. Figure 1 illustrates the relationship between ACEC and the SMB in chart form.

The terms of reference for ACEC today state, “the object of ACEC is to be at the disposal of the Standardization Management Board (SMB), to advise on, guide and coordinate IEC work relating to electromagnetic compatibility matters, in order to avoid duplication and conflict in IEC standards.”^[2]The coordination activities relate to electromagnetic emissions, coupling, and immunity to disturbances and cover: definitions, instrumentation, methods of measurement, requirements and limits, codes of practice, and characterization and classification of the electromagnetic environment. ACEC also gives guidance to the IEC Central Office on documentation for EMC, which includes brochures, workshops, web pages and other forms.

ACEC is currently composed of four members each nominated by CISPR and TC 77 (EMC) and four additional independent experts knowledgeable in EMC matters, but not representing other technical committees that are members of ACEC; presently the four ACEC experts are from Belgium, Canada, Germany, and Japan. Besides these 12 members, members come from product committees whose activities include EMC aspects as an important part of their work. Currently, there are six committees participating in ACEC work. They are TC 22 (power electronic systems and equipment); TC 46 (cables, wires and waveguide components); SC 62A (common aspects of electrical equipment used in medical practice); TC 64 (electrical installations and protection against electric shock); SC 65A (industrial process controls—system aspects); and TC 108 (safety of electronic equipment including information technology).

ACEC meets twice per year to discuss progress within the IEC and to receive reports from the members concerning the status of EMC work. From time to time, conflicts among IEC committees involving EMC standards (either under development or under revision) arise, and these are discussed within ACEC. When a conclusion is reached, recommendations for resolution are submitted to the SMB for decision. As the Chairman of ACEC over the past 11 years, I have made an effort to move some of the meetings from Geneva to different parts of the world to allow local IEC National Committees to participate in the meetings and to equalize the travel expenditures for the members. Since 1996 ACEC has met in London, Paris twice, Stockholm, Erlangen twice, Beijing, Piscataway (New Jersey) twice, Tokyo, Copenhagen, and Honolulu. The next two meetings are planned for Singapore and Brussels.

IEC GUIDE 107

IEC Guide 107 is entitled, “Electromagnetic Compatibility—Guide to the Drafting of Electromagnetic Compatibility Publications.”^[3] This guide was first written in 1989 by the ACEC, and the second edition (published in 1998) is under revision at this time largely to take into account some changes in the definition of horizontal standards and committees within the IEC. It is the comprehensive guide that defines the different types of EMC standards within the IEC and is a handbook on how to write these different types of EMC publications. The publication includes a description of its scope and intent: “This guide describes procedures for the drafting of IEC publications, which relate wholly or partly to electromagnetic compatibility (EMC). They should be applied when preparing new electromagnetic compatibility publications or EMC clauses as well as when revising existing publications. These procedures should be followed in order to ensure that the resulting publications are consistent with each other and current practice, and to avoid overlapping document scopes.”

In particular, IEC Guide 107 describes the principal types of EMC standards, which provide emission limits and immunity requirements. There are four types of publications that are defined in the guide including:

• Basic EMC publications
• Generic EMC standards
• Product family standards
• Product standards

Some information from Guide 107 concerning these types of publications is summarized below.

Basic EMC publications give the fundamental principles, concepts, terminology or technical characteristics for the achievement of EMC and serve as reference documents for product committees. These publications are usually developed by TC 77 and CISPR/A and may be standards, technical specifications, or technical reports. They are general in nature and hence are not dedicated to EMC for specific product families or products. The most famous of these types of basic EMC publications are found in the IEC 61000-4-x series covering measurement and test techniques. It is important to note that basic standards should not include prescribed limits and/or specific performance criteria. These are covered by the generic, product family or product standards.

Generic EMC standards are designed to apply, for a defined electromagnetic environment, to products for which no dedicated product family/product EMC standards exist. They specify a set of essential requirements, test procedures, and generalized performance criteria applicable to such products or systems operating in this electromagnetic environment. Product committees should determine if the tests, test levels, and performance criteria for the particular electromagnetic environment covered in a generic EMC standard are adequate for their products before developing a separate product EMC standard.

Product family/product EMC standards apply to a product family, which is a group of similar products for which the same standards can be applied or to a specific product type. Product family/product EMC standards define specific emission and immunity requirements, as well as measurement and test procedures dedicated to particular product families/products. They should indicate the relevant installation and operating conditions. They should also give precise performance criteria, taking into account the purpose of the equipment wherever possible. The principal IEC EMC product families include:

• Multimedia equipment including: radio and TV receivers and associated equipment; information technology equipment (ITE); telecommunication equipment (as far as it is within the scope of the IEC); and power line telecom (PLT) terminal equipment
• Household and commercial equipment (other than ITE)
• Industrial-process measurement and control equipment (other than ITE)
• Traffic and transportation equipment
• Utilities equipment (electricity, gas, water, etc.)
• Medical equipment
• Measuring and test equipment
• Equipment connected to the HV, MV and LV public mains networks.

Given this well-defined structure for EMC publications, it is the job of ACEC to ensure that these standards are developed in a consistent manner and that they do not conflict with each other. Some examples will be mentioned later in this article.

MAJOR ACCOMPLISHMENTS BY ACEC

Over the past 11 years, this author has had the opportunity to observe and to participate in several important accomplishments of ACEC. Some of these are summarized below:

1. Resolution of a long-standing disagreement between PC manufacturers and electric power system suppliers dealing with the harmonic emission limits required for personal computers. Long negotiations were required over nearly 10 years with Mr. Georges Goldberg (Switzerland), Prof. Eisuke Masada (Japan), and Dr. William Radasky (U.S.) leading the ACEC negotiation efforts. Finally, compromise emission limits were accepted by the PC industry along with a simplification of test methods by the power industry.
2. ACEC formed an ad hoc group to study the need for forming a new IEC technical committee dealing with measurement methods for evaluating limits for human exposure to electromagnetic fields. This work was led by Mr. Georges Goldberg and resulted in the establishment of TC 106 (methods for the assessment of electric, magnetic and electromagnetic fields associated with human exposure) by the SMB.
3. Because of the difficulties in tracking over 100 product EMC standards as they were developed and revised, a system was set up by ACEC for the electronic survey of all new standards being developed by the IEC and for review of these product standards while they were still in a draft form. Prof. Michel Ianoz (Switzerland) has chaired this effort for many years with the support of several ACEC reviewers and the ACEC Secretary, Dr. Rémy Baillif (IEC Central Office).
4. ACEC recommended the formation of an “EMC Zone” on the IEC website (www.iec.ch) to inform those working in the IEC where important EMC information could be found. In addition, a portion of this website is designed for the public to learn about EMC. Mr. Peter Kerry (U.K.) was instrumental in the development of the “EMC Zone,” and he was also active in the preparation of the “Guide to Guide 107”—a pamphlet that provides an overview of IEC Guide 107.
5. ACEC also initiated a comprehensive EMC Workshop Program both for IEC Delegates and for industrial groups throughout the world. Members of ACEC participated in workshops held during the annual IEC General Meetings beginning in 2000 in Stockholm and continued in Florence, Beijing, Montreal, Seoul, Cape Town, Berlin, and Paris (2007). The next IEC ACEC EMC Workshop is planned for Sao Paulo, Brazil in November 2008. The industry workshops have been supported strongly by Dr. William Radasky (U,S,), Mr. Diethard Moehr (Germany) and Mr. Don Heirman (U.S.) and have been held in the United States, Cuba, China, Brazil, Argentina, Iran, Japan, Malaysia, and Vietnam. Workshops are planned for Singapore and Romania in 2008.
6. To increase the efficiency of existing test methods and to establish new test methods for both immunity and emissions, ACEC supported the development of joint task forces (JTFs) between SC 77B and CISPR/A. This work was coordinated by Jacques Delaballe (France) and Don Heirman (U.S.) and has resulted in new standards dealing with TEM Waveguides (61000-4-20) and Reverberation Chambers (61000-4-21). Work is continuing to revise both of these standards and to develop a new standard on the use of fully absorber-lined rooms (FAR).

EMERGING ISSUES FOR ACEC

Over the past few meetings, several topics and questions appear to be emerging as important future issues for ACEC.

• One major issue is the development of PLT (power line telecommunications) to provide Internet access to users over power lines. The emissions from PLT may interfere with radio communications in some cases. There are ongoing discussions concerning whether emission limits are needed for this service.
• Another major issue is how to promote new test methods (such as TEM cells or reverberation chambers) when it is not always possible to provide new methods that correlate readily to older test methods (such as semi-anechoic chambers).
• Can ACEC help promote the development of measurement uncertainty factors to be used in the evaluation of immunity tests?
• How will the power system harmonic emissions standards adapt to future changes in consumer electronics, without a firm agreement concerning the best procedures for controlling low frequency emissions?
• Will ACEC be able to work more closely with the ISO to ensure that there is not a duplication of the development of basic EMC standards?
• Will ACEC be able to continue to promote IEC EMC standards to be used throughout the world to minimize regulatory burdens on manufacturers?

SUMMARY

ACEC and its predecessor have been active in the IEC in coordinating the work of electromagnetic compatibility (EMC) since 1978. Since that time, ACEC has developed a unique structure for EMC publications that is used to this day in the IEC and in other regional standardization organizations. ACEC is an active committee and has solved several important problems for the IEC EMC community. ACEC continues to work on emerging EMC issues often created by the development of new electronic products, services, or test methods.

Readers who are interested in the work of ACEC or who wish to submit questions or topics to the committee are encouraged to contact the ACEC Secretary, Dr. Rémy Baillif, at rb@iec.ch.

REFERENCES

1. Personal Communications with Dr. Rémy Baillif, Secretary of ACEC, January 2008.
2. “Terms of Reference for ACEC,” CA/2143/INF, 30 November 2001.
3. IEC Guide 107, “Electromagnetic Compatibility—Guide to the Drafting of Electromagnetic Compatibility Publications,” Edition 3, 2008 (Draft).

William A. Radasky received the B.S. degree with a double major in Electrical Engineering and Engineering Science from the U.S. Air Force Academy in 1968. He also received the M.S. and Ph.D. degrees in Electrical Engineering from the University of New Mexico in 1971 and the University of California, Santa Barbara in 1981, respectively.

Dr. Radasky’s current interests include studies to understand the threat of Intentional EMI and to develop mitigation and monitoring methods to protect facilities from this new threat. He is Chairman of IEC Subcommittee 77C, which is developing high-power electromagnetic protection and test standards for civil systems. He is also the Chairman of TC-5 (High Power EM) for the IEEE EMC Society. Other IEMI activities include his role as Associate Editor for the IEEE EMC Transactions special issue on IEMI in 2004 and as chair of the IEEE Standards Working Group to provide protection guidelines for publicly accessible computers from the threat of IEMI. In addition he is the Chairman of the IEC Advisory Committee on EMC (ACEC), which is tasked to coordinate all EMC standardization work for the IEC. He is an EMP Fellow and a member of the Eta Kappa Nu and Tau Beta Pi honor societies. In October 2004 he was presented the Lord Kelvin Medal in Seoul, South Korea by the International Electrotechnical Commission for exceptional contributions to international standardization.