Automotive EMC standards are among the world’s most dynamic. This especially is true today when companies around the world are working to harmonize their internal standards with appropriate international standards. In addition, many of the national standards bodies are striving to reach consensus to align their standards with the published international standards.
To appreciate this balance of national and international standards, it’s important to understand the structure of the two types of writing bodies and their relationships to one another. To illustrate, the U.S. standards are listed in Table 1 with short descriptions and cross-referenced to their international standard counterparts in Tables 2 and 3.
Standards Writing Bodies
National and international standards are the creation of teams of dedicated experts around the world, each working to produce the most technically sound and economically responsible standards they can implement for specific products. Since the international standards committees deal with a number of languages, cultural differences, economic constraints, and technical viewpoints, it is remarkable that there are so few significant technical differences to be overcome.
International Standards
International standards for automotive applications fall under two standards organizations:
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International Organization for Standardization (ISO) TC22/SC3/WG3 for immunity concerns.
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Special International Committee for Radio Interference (CISPR), part of the International Electrotechnical Commission (IEC), which is responsible for emissions for all products. Subcommittee D addresses automotive and related products.
For the most part, all significant automotive EMC test methods have international versions as one of the tests within the ISO and IEC.
U.S. Standards
The American National Standards Institute (ANSI) is the U.S. standards coordinating organization, and all representation on international standards committees is authorized by ANSI. In the automotive product field, ANSI has delegated the standards-writing activity to the Society of Automotive Engineers (SAE).
Along with educational and other activities, SAE is a standards-creating body. SAE, through its two primary automotive EMC committees, Electromagnetic Immunity (EMI) and Electromagnetic Radiation (EMR), has developed an extensive collection of EMC standards.
CISPR 25
SAE J1113-42
DIS ISO 7637-2
Table 2. Emissions Standards Cross-Reference
The SAE EMI Standards Committee addresses immunity of automotive electrical and electronic systems in the vehicle and the modules or components of the vehicle. This committee also serves as the core group for the U.S. Technical Advisory Group (USTAG) for ISO/TC22/SC3/WG3.
The SAE EMR Standards Committee primarily is concerned with emissions from a vehicle and its modules or components that may cause radio-reception interference. The USTAG for CISPR/D is a subset of this committee.
Current Status of EMC Standards
As shown in Table 1, the SAE does not accept the stripline test method as a creatable, repeatable test method. Also, the ISO has not adopted several of the long-accepted SAE test methods. This is due, in part, to the European view that an international standard is likely to be used as a regulation, and there is great pressure to limit the number of test methods adopted as international standards.
Table 3. Immunity Standards Cross-Reference
What about U.S. automotive-industry commonality for component requirements? A look at the requirements of DaimlerChrysler, Ford, and GM shows that there is common acceptance, although with some detail variations, in the use of the SAE J1113-41 Emission Test, the J1113-4 BCI Test, the J1113-11 Conducted Transient Immunity Test, the J1113-12 Coupled Transient Immunity Test, and the J1113-21 Radiated Immunity Test.
All three companies have developed global EMC standards. As a result, each of them references international versions of the documents. The SAE Automotive EMR and EMI Standards Committees remain committed to harmonizing the SAE documents with the international documents to the extent technically acceptable.
Although many countries around the world have implemented automotive EMC regulations in this age of extensive regulations, the U.S. government has not. Instead, radio interference was addressed by the U.S. automotive industry more than 50 years ago.
At that time, an agreement was reached between the automotive industry, represented by the Automobile Manufacturer’s Association (later the Motor Vehicle Manufacturer’s Association and the AAMA, now disbanded), and the FCC. In essence, the agreement stated that if the manufacturers designed to meet the requirements of SAE J551 (now SAE J551-2) and the FCC did not receive a significant number of consumer complaints, the FCC would not implement regulations related to automotive transportation.
Today, there remains a clause in CFR 47 Part 15 that exempts transportation electronics from reporting to the FCC regarding compliance with Part 15. Through the efforts of the SAE standards committees and the automotive companies acting responsibly, additional regulation has been averted. We hope the industry will continue to act responsibly and that automotive EMC regulations will not be needed in the United States.
About the Authors
Poul Andersen has been an active part of the automotive EMC community for decades, participating in SAE, ISO, and CISPR committees. Currently, he is chairman of CISPR Subcommittee D and the SAE EMR and EMI Standards Committees. Mr. Andersen retired from DaimlerChrysler earlier this year and has initiated an automotive EMC consulting business. He graduated from Wayne State University with a B.A. in physics and a B.S.E.E. and later obtained a professional development in management degree through Chrysler and the University of Michigan. Poul Andersen Consulting, 37249 Hebel Rd., Richmond, MI 48062, 586-727-1964,
e-mail: [email protected]
Kimball Williams joined Underwriters Laboratories as a staff engineer after 26 years as a principal EMC engineer at Eaton. His professional affiliations include serving as the U.S. delegate to IEC/CISPR/D and membership in the IEEE EMC Society Board of Directors and current president-elect, the IEEE EMC Society Standards Committees, and the SAE EMI and EMR Committees. Mr. Williams is a National Association of Radio and Telecommunications Engineers (NARTE)-certified EMC engineer and a member of the board for NARTE and holds a B.S.E.E. from Lawrence Technological University. Underwriters Laboratories, 25175 Regency Dr., Novi, MI 48375, 248-427-5325, e-mail: [email protected]
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December 2003