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Keeping Current with Vehicle EMC ApprovalsVehicle manufacturers and electronics suppliers must stay abreast of an evolving regulatory environment to guarantee the proper design, testing, and use of their products.
Vehicle manufacturers and their suppliers of electrical and electronic equipment have always ensured that their products are correctly designed and tested for use in the highway's EMC environment. Until recently, aftermarket electrical and electronic equipment had either been tested to standards written for the nonautomotive industry or to ISO standards written for automotive applications. Today, however, the requirements of the European EMC Directive—89/336/EEC—have been met by the vehicle industry with a number of specific directives and standards, which are outlined in this article. To summarize briefly, these specific directives and standards include the following: the European Automotive EMC Directive, 95/54/EC, which provides the EMC approval regimen for motor vehicles of four wheels or more and all equipment (including aftermarket equipment) intended to be fitted to them; the EMC chapter of the multidirective for two- or three-wheeled vehicles, 97/24/EC, which provides the approval regimen for these vehicles and their equipment; Regulation 10.02 of the United Nations Economic Commission for Europe (ECE), which provides similar EMC requirements; Directive 2000/2/EC, which amends Directive 75/322/EEC to create an EMC directive for forestry and agricultural tractors; an ISO standard for forestry and agricultural tractors and equipment, which is published as an EN; an ISO standard for earth-moving machinery; and prEN 13309, which is a draft CEN standard for construction equipment with internal electrical power supplies. In addition to addressing the relationship of the above
standards and directives to the general EMC directive, this article
also includes interpretations for various vehicles and their components,
as well as discussion of the implications for the various types
of aftermarket components.
Vehicles and 89/336/EEC The generic EMC Directive, 89/336/EEC, was published in 1989
and came into full effect on January 1, 1996. It applies to all
electrical and electronic equipment. Article 2.2 of the directive
provides an exemption for apparatus covered by a product-specific
directive.
The European automotive industry already had a relevant directive, 72/245/EEC, which covered the suppression of radio interference from spark ignition engines. But the industry initiated an amendment to 72/245/EEC—known as the Automotive EMC Directive, 95/54/EC—to provide harmonized EMC protection requirements for most vehicles of four wheels or more and for all devices intended to be fitted to them. This directive ensures that vehicles operate safely in their electromagnetic environment and do not emit excessive levels of electromagnetic radiation. It also includes aftermarket equipment to ensure that the essential requirements for vehicle type approval are not compromised. As mentioned previously, chapter 8 of the European multidirective, 97/24/EC, provides a similar approval route for two- or three-wheeled vehicles, and Directive 75/322/EEC—as amended by 2000/2/EC—will provide a similar approval route for forestry and agricultural tractors when it comes into force. As a result, under the terms of Article 2.2 of 89/336/EEC, the vehicles, components, and systems covered by all three of these directives have been taken outside the scope of 89/336/EEC. ECE Regulation 10.02 provides a combined EMC approval
for vehicles covered by 95/54/EC and for those covered by 97/24/EC.
(ECE membership countries are more than just the European countries.
Each ECE member country decides at the national level whether
to recognize an ECE regulation as meeting national vehicle approval
requirements. Some non-ECE member countries also accept an ECE
regulation as the equivalent to their national requirement.)
Of course, some vehicles are not covered currently by vehicle EMC directives. These include forestry and agricultural tractors until October 1, 2001. The standard EN ISO 14982 covers forestry and agricultural tractors and all kinds of mobile (including handheld) agricultural machinery, forestry machinery, and landscaping and gardening machinery. ISO 13766 covers earth-moving machinery as defined in ISO 6165, and prEN 13309 covers construction equipment machines with internal electrical power supply. These standards provide the guidance to enable these vehicles to show compliance with 89/336/EEC.
It should be noted that 89/336/EEC is a new approach directive that allows manufacturers to put a CE mark on a product when they are satisfied it meets the requirements of the EMC Directive and other relevant directives. The ISO standards provide guidance to EMC competent bodies for assessing the vehicle types identified in their titles. Where EN ISO 14982 is applicable, it is possible for the manufacturer to declare compliance with this standard without the use of an EMC competent body. On the other hand, Directives 95/54/EC, 97/24/EC, and
75/322/EEC are so-called old approach directives and as such require
the manufacturer to submit samples of its product to a member
state's vehicle approval authority for testing by a technical
service. ECE Regulation 10.02 requires the same approval process.
In the United Kingdom, the Vehicle Certification Agency (VCA)
is both approval authority and technical service. A technical
service carries out all the technical work required to show that
a product complies with the directive and presents this to the
VCA to enable it to issue an approval certificate and approval
number incorporating an "e" mark for EC directives or an "E" mark
for ECE regulations. (Please note that "e" and "E" marks are different
from a CE mark. See Table I.)
Features of 95/54/EC The Automotive EMC Directive, 95/54/EC, applies to "any vehicle intended for use on the road, being complete or incomplete, having at least four wheels and a maximum design speed exceeding 25 km/hr, and its trailers, with the exception of vehicles which run on rails and of agricultural and forestry tractors and all mobile machinery." Its scope includes all electrical and electronic equipment—both aftermarket and original equipment—intended for installation in such vehicles. In this case, equipment is defined as a component (a device that is automotive type approved for installation in all vehicles to become part of the vehicle) or a separate technical unit (a device that is automotive type approved for installation in specified vehicles). Any device—original fit or aftermarket—that fits within the above definitions falls within the scope of 95/54/EC and, as a result, falls outside the scope of 89/336/EEC. The only approval mark for automotive equipment that provides freedom of movement across Europe is the automotive type approval "e" mark. In cases in which a device is also suitable for use
in areas not covered by the above definitions, the device also
falls within the scope of 89/336/EEC and must be CE marked for
these areas of nonautomotive application.
When considering the definition of a component, it is
necessary to recognize the meaning of "installation as part of
the vehicle." For example, an electric compressor that is temporarily
plugged into the accessory socket (cigarette lighter) to inflate
the tires while the vehicle is parked is not part of the vehicle.
The essential features of 95/54/EC are summarized below:
Features of 97/24/EC The multidirective for two- or three-wheeled vehicles
was adopted on June 17, 1997. Chapter 8 of this directive covers
EMC for such vehicles and the separate technical units (STUs).
Key provisions of 97/24/EC include the following:
Chapter 8's title is "Electromagnetic Compatibility of Two- or Three-Wheel Motor Vehicles and Electrical or Electronic Separate Technical Units." Its definition of an STU is different from that given in 95/54/EC in that the component approval of an STU is for installation in any vehicle type or in a specific vehicle type or types. An electrical or electronic component sold as aftermarket equipment that is not exclusively designed for two- or three-wheeled vehicles may either comply with this directive or comply with the general EMC Directive 89/336/EEC. Remember that compliance with 89/336/EEC requires suitability for the vehicle environment, not the domestic environment. This appears to allow the fitting of an electronic subassembly type approved as a component to 95/54/EC. The emission and immunity requirements outlined in 97/24/EC
have the same reference levels as 95/54/EC, as well as the same
type approval and Conformity of Production (CoP) levels. However,
there are a number of differences in the testing methods to
allow for the testing of different vehicle types.
Features of 2000/2/EC Directive 2000/2/EC adapts to Technical Progress
Council Directive 75/322/EEC, amending it into a tractor EMC
directive that is considered as a specific directive for the
purposes of Directive 89/336/EEC, Article 2.2, beginning on
October 1, 2001. This directive provides that
Replacement parts for vehicles not approved to 75/322/EEC as amended do not need to comply with this directive. For purposes of this directive, forestry and agricultural tractors are defined as motor vehicles that feature wheels having two axles; are fitted with pneumatic tires; have a designed speed between 6 and 40 kph; have a main function of tractive power, power tools, machinery, or trailers are designed to tow, push, carry, or ; and are intended for agricultural or forestry use.Features of ECE Regulation 10.02 ECE Regulation 10.02 is based on 95/54/EC for
technical content, and additional features have been incorporated
to include the relevant features of 97/24/EC. As a result,
this regulation is applicable to vehicles with two and
three wheels, as well as those with four or more wheels.
Features of EN ISO 14982, ISO 13766, and Draft Standard prEN 13309 These "off-highway vehicle" standards and the draft standard are applicable to both the whole vehicle and to electronic systems used as components in the vehicle. The scope of EN ISO 14982 is important in that it covers all kinds of mobile (including handheld) agricultural machinery, forestry machinery, and landscaping and gardening machinery, as well as forestry and agricultural tractors. All three of these standards use RF emissions test specifications equivalent to those of 95/54/EC as their requirements. Additionally, they specify ISO 11451 and ISO 11452 immunity test standards for the whole vehicle and the equipment and components, respectively. They also specify the test methods and immunity levels for the relevant ISO test standards so that the RF immunity requirements of 95/54/EC are achieved. In addition to the 95/54/EC requirements, these standards include an electrostatic discharge (ESD) test of the whole vehicle as well as component tests for supply transients and ESD so that the test requirements are identified to cover the EMC environment of the vehicle or equipment. (This is necessary, as CE marking under 89/336/EEC requires a product to be suitable for its environment.) The correct use of these standards by an EMC competent body and a manufacturer should ensure that all vehicles and equipment used in public places meet the same high requirements for emissions and immunity as vehicles subject to type approval. It should be noted that—for forestry and agricultural tractors—under the amended 75/322/EEC, Directive 89/336/EEC will not apply to these vehicles after October 1, 2001. Type Approval The type approval procedure under Directives
95/54/EC, 97/24/EC, and ECE Regulation 10.02 is essentially
the same for vehicles as for components. The same procedure
will also be followed for 75/322/EEC (as amended by 2000/2/EC)
beginning January 1, 2001.
To obtain type approval in the UK under these directives, it is necessary to apply to the technical service. The process begins with the technical service issuing a VCA job number and informing the VCA so that it can begin CoP assessment of the client. The client provides the documents specified in the directive—along with the required number of sample products for assessment and testing—and then prepares a worst-case analysis of the product range, together with a draft test plan. This analysis is assessed during a worst-case review meeting with the technical service. (In cases in which the product is a single product, this meeting may simply be a document exchange. In cases involving a number of products derived from a basic design, the products are assessed to identify a worst-case version for testing to limit the amount of test work to be carried out.) Next, a documented worst-case assessment is produced for the approval body as a record of the agreement. The test plan is then finalized, and the type approval fees are confirmed. Testing is carried out on the sample product(s), with the technical service witnessing the test work as necessary. (The directive defines the permitted test methods and test limits to be used for both vehicles and components for radiated immunity and for radiated emissions.) Finally, test reports are prepared, and the
technical service provides a complete set of these reports
as well as technical documentation to the approval authority.
Subject to a satisfactory review of the submitted documents
and CoP assessment, the approval body issues a type approval
certificate, which authorizes the manufacturer to put
the "e" or "E" mark on the product(s).
Vehicle Type Approval The worst-case review considers the vehicle type and variants against the requirements of the relevant directive to identify the vehicle to be tested. A vehicle is only tested for immunity if there are electronic systems in the direct control of the vehicle. However, immunity testing is monitored for either failure of direct control or behavior of other systems likely to mislead other road users. Where equipment is not operated during the defined RF immunity testing, the technical service must be provided with technical evidence showing that the equipment does operate correctly in the presence of high RF fields. All electrical components fitted to the vehicle
gain approval as separate technical units, as they are
all tested by the whole vehicle testing. If a manufacturer
decides later in the life of the vehicle that it wishes
to change a component, it may do so if the replacing component
is type approved and the approval body agrees to the change.
Component Type Approval The worst-case review is carried out prior to
testing for type approval. In cases where the component
is actually a family of components, the worst-case review
identifies a representative member of the "family" for
testing. If, during the worst-case review, the component
is assessed to be one that affects the direct control
of the vehicle, then it must be subjected to witnessed
radiated immunity testing. If the component contains an
oscillator with a frequency greater than 9 kHz, the radiated
emissions tests will be for both narrowband and broadband
emissions. And when the component includes an intentional
transmitter, the manufacturer is required to provide technical
evidence to the technical service to show that—when correctly
installed—the normal operation of a vehicle will not
be affected.
It is the responsibility of the component supplier to ensure that its product is "fit for purpose" when installed in the vehicle. To this end, the supplier may choose to carry out appropriate testing for electrical transients, ESD, and other EMC phenomena to show that the product is suitable for typical vehicle EMC environments. These tests are at the discretion of the equipment supplier and are not part of type approval testing. Domestic and Business Products
In order to earn approval under Directive 89/336/EEC, a product must be proven suitable for use in its specified working environment. A product specified for domestic and business use that is CE marked for vehicle use in addition to its normal domestic and business use should have technical justification in its manufacturer's technical construction file to show it complies with a typical vehicle's EMC environment. The file should include user instructions that fully cover safe use in a vehicle. An EMC competent body advising on this area should have vehicle EMC expertise. If a vehicle manufacturer advises against the use of specific equipment of this nature, it cannot be used in that vehicle. Communications Equipment In instances involving communications equipment intended for installation in a vehicle, the equipment is subject to automotive EMC type approval. (The radio type examination route to CE marking for EMC identified in Directive 89/336/EEC is replaced by automotive type approval.) Automotive EMC type approval for communications equipment—which provides freedom of movement for the equipment across Europe—is a separate requirement from that of radio type approval for radio spectrum management. Beginning April 8, 2000, the European Directive 1999/5/EC will have changed the approval regimen for radio equipment. From this date radio equipment will have to be CE marked under that directive and will also need to comply with the automotive type approval requirements. Part of this automotive EMC type approval includes showing by technical evidence that—while transmitting—the communications equipment does not affect the normal operation of a vehicle. Installation procedures, instructions for operation, and technical evidence should be such that when correctly followed, the required level of immunity for typical vehicles and their electronic systems is achieved. Where a vehicle manufacturer advises against
the use of specific communications equipment, its advice
should be accepted.
CE Marking for Vehicles Not Subject
to Harmonized European standards (ENs) that are appropriate for all vehicles/equipment for assessment under 89/336/EEC do not currently exist. It is recognized that the vehicle's (public place) EMC environment is severe, and in many cases the equipment affects the safe, reliable operation of the vehicle/equipment. The technical construction file route identified in 89/336/EEC provides the route by which the requirements of 95/54/EC and other relevant international standards for a vehicle's EMC environment may be used for testing. The EMC competent body now has guidance available from ISO 13766 and prEN 13309. It is expected that, in the future, the ISO standard will be converted into an EN and the prEN will become an EN. ISO 14982 has been adopted as EN ISO 14982,
and manufacturers may CE mark forestry and agricultural
tractors and all kinds of mobile (including handheld)
agricultural machinery, forestry machinery, and landscaping
and gardening machinery by testing to and declaring compliance
with this standard as part of a technical construction
file. It should be noted that, under the amended 75/322/EEC
directive, 89/336/EEC will not apply to the tractors defined
in Directive 75/322/EEC after October 1, 2001. Type approval
will be possible beginning January 1, 2001.
Vehicle Security Products Many vehicle security products are electronically based and use low-power radiocommunications equipment for remote control. These products have a specific automotive directive, 95/56/EC, with similar requirements in ECE Regulation 97. The requirements of 95/54/EC are fully applicable to vehicle security products, but the requirements of 95/56/EC will take precedence in some respects. Compliance with 95/56/EC was required for new
type vehicles and security devices beginning January 1,
1997, and was required for all existing types from October
1, 1998. If a radio transmitter is part of the security
system, it must comply with the requirements for radio
type approval as well as the automotive type approval
requirements.
Conclusion There can be little doubt that, with more technological
advances being made and new applications for existing
equipment being discovered, the world's regulatory environment
will be one constantly in development. By keeping up with
the ongoing changes to applicable EMC standards and directives,
vehicle manufacturers and suppliers of electrical and
electronic equipment can ensure the proper design, testing,
and use of their products in the current EMC environment.
Terry Beadman is the certification
and inspection manager of the electrical group at Motor
Industry Research Association (MIRA) and represents the
organization on many automotive industry technical committees,
as well as a number of general committees, for the EMC
industry. He has provided the EMC competent body service
within MIRA since 1992, and he also provides the VCA's
technical service for EMC and antitheft automotive type-approval
work carried out at MIRA. Prior to joining MIRA in 1988,
Beadman worked in the aerospace, process control, and
nuclear power industries. He may be contacted via e-mail
at terry.beadman@mira.co.uk.
The information presented in this article is based on information gathered by the UK's Automotive EMC Club, which was established as part of the UK DTI's EMC club scheme in 1993. The club is operated by MIRA as a service to the international automotive industry and its suppliers. For more information or advice on a vehicle-related EMC matter, contact the Automotive EMC Club by phone at +44 2476 355495 or by fax +44 2476 355486. Illustration by James Schlesinger |
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