Find the Right Standard to Comply With the LVD

The Low-Voltage Directive (LVD) is not new. It has existed since 1973 but only became mandatory in 1997 and requires the CE Marking. The LVD is applied to end- user electrical equipment that operates from 50 VAC to 1,000 VAC or from 75 VDC to 1,500 VDC. The electrical product can be a component, but typically it is complete equipment.

If you think the LVD applies to your product, then you must test it to the appropriate standard. It sounds easy. But how do you locate the correct standard for your product? Keep in mind that the LVD does not stipulate which standards are applicable to which product categories.

The Guideline on the Application of Council Directive 73/23/EEC (LVD) states that no CE Marking is needed on components that rely on the end equipment for their safety, said Dave Lohbeck, senior product safety consultant at Dell Computer. This means that the CE Marking is not valid on the majority of components.

The scope of the LVD includes electrical products intended for incorporation into other equipment and those electrical products that are end items in themselves. Depending on how they are integrated into the final product, some types of electrical components may need a CE Marking.

The guideline gives examples of products that require a CE Marking. Mostly, these are components used in building installations such as household switches, lamps, fluorescent light starters, fuses, and some motors and transformers.

The LVD sets down the basic premise that electrical products must be proven safe, said Eric Tenody, product safety manager at Instrument Specialties. The concept of safeness addressed by the directive is analogous to what Underwriters Laboratory (UL), the Canadian Standards Association (CSA), and the Nationally Recognized Testing Labs have imposed on products used in North America.

Consult the Official Journal (OJ) of the European Communities for listings of standards with product groupings, said Mr. Tenody. You can turn to Notified Bodies, accredited labs, and product safety consultants to find out if your particular product needs to be evaluated for LVD compliance.

The OJ specifies technical standards which outline the basic construction and test requirements for particular products, said Jonathan Kotrba, Senior Engineer at TUV Rheinland. Journal C210, Volume 35 contains directives including the LVD. It provides a list of standards drawn up by common agreement among the members of the EU. The list is continuously revised, and typically updated releases become Euro Norm (EN) standards.

Although the LVD does not directly state which standards to use, it does contain, as an attachment or amendment, the standard or technical rule needed to test your product, said Dell’s Mr. Lohbeck. For computers, it is EN 60950 and IEC 950; for electronic household devices, look at EN 60065 or IEC 65. Check EN 61010-1 or IEC 1010-1 for test and measurement devices.

The best place to look for relevant standards regarding safety design, test and pass/fail criteria is the EU Notified Bodies, agreed Mr. Lohbeck. These Notified Bodies are sanctioned by the European Commission to select and interpret the standards.

There also are some information and technical-help services that are operated by or in conjunction with the Notified Bodies, said Mr. Lohbeck. One service is Technical Help for Exporters provided by BSI in the United Kingdom.

Also, contact a Notified Body if there is no standard that applies to your product or if you are not sure of the current ruling by the European Council, added TUV Rheinland’s Mr. Kotrba. They are listed in Journal C210 Volume 35.

Sometimes a product falls into more than one category and more than one directive, said Instrument Specialties’ Mr. Tenody. The manufacturer must ensure compliance to all applicable requirements. Within the LVD, if equipment spans more than one category, a complimentary dual evaluation must be performed to ensure that the worst-case requirements are addressed.

Selecting the standard is the easy part, said Mr. Lohbeck. Making the proper interpretation is the challenge. If you use the European Notified Body for the testing process, you can be confident the selection and interpretation of the standard will be correct.

To locate the standards that apply to your product, one resource is, The New Approach, said Andrew Bergman, vice president of Qualified Specialists. This book is a joint effort between the European Committee of Normalization (CEN) and the European Committee on Electrotechnical Standardization (CENELEC), and it contains a comprehensive listing of all EN standards and preliminary (prEN) standards. Many of them are just transposed IEC standards.

The book provides a description of the scope and purpose of each standard. It is important to review this information to ensure you have designed your equipment in accordance with all the applicable standards.

The LVD is a new-approach directive because it allows regulations to be introduced without relying on standards. New-approach status is achieved by removing the mandatory requirement to meet the standards.

To comply with the LVD new-approach directive, you must demonstrate that your product meets essential requirements and that the conformity assessment procedures have been followed. However, meeting the requirements of the standard is not legally mandated.

Annex II of the LVD lists equipment outside the scope of the directive. This includes electrical equipment for radiology and medical purposes and equipment affected by radio electrical interference. The products used for medical purposes are accounted for by the Medical Directive. The EMC Directive covers the radio electrical interference, but it must be applied alongside, but separately, to the requirements for the LVD.¹

Other references that can help you find information on the LVD, CE standards, and various approval issues are listed in Table 1. For more sources about standards information, contact John Allen, president of Product Safety Consulting.

Similarities to NA Standards

Products tested to North American standards that existed prior to the harmonization with the IEC-based documents generally will not comply with the EN standards necessary for LVD compliance, said Instrument Specialties’ Mr. Tenody. Although the LVD has been in place since 1973, its enforcement through the CE Marking directive has put many North American manufacturers in a tailspin, struggling to design products for these sometimes more stringent European requirements.

The UL is following the CSA’s lead in adopting IEC standards, said TUV’s Mr. Kotrba. In Europe, an adopted IEC standard typically becomes an EN standard. For example, the IEC 335 series of appliance standards was adopted by the EC, modified where appropriate, and renamed EN 60335.

A UL advisory letter dated August 15, 1997, to applicable advisory councils and subscribers stated that UL is developing harmonized household appliance standards to the IEC 335. Other UL standards based on IEC standards and harmonized with the EN requirements include UL 3101 (EN 61010), the laboratory equipment standard, and UL 1950 (EN 60950), the business equipment standard.

Although the UL 1950 adopted the EN 60950 standard, there still are difficulties to work out, said Dell’s Mr. Lohbeck. Presently, there are more than 200 allowed deviations and U.S. interpretations are not in line with the EU point of view. Additionally, UL 1950 is not yet listed in the OJ of the European Community.

Where harmonized standards exist, industry has reaped the benefits of healthy competition, said TUV’s Mr. Kotrba. It becomes easier for European labs to obtain the Nationally Recognized Testing Lab status and for the UL to obtain the CB, the international approval scheme status.

The CB Scheme is the closest procedure available for getting multiple approvals with one set of tests, said Product Safety’s Mr. Allen. The participants of the CB Scheme are the member organizations of the IECEE and have National Certification Bodies (NCB). At the national level, the NCBs operate a safety certification or approval scheme for electrical products. As of June 1997 there were 45 NCBs in 34 countries registered under the CB Scheme.

The idea behind the CB Scheme is to have your product tested at one NCB, get a CB certificate, and submit your product to another NCB with little or no additional testing, said Mr. Allen. Typical approval times among members are approximately two weeks.

Reference

1. Clements, V., “Meeting the Product Safety Requirements for CE Marking in the European Union,” IEEE International Symposium on Electromagnetic Compatibility, 1997, pp. 8-13.

The following companies contributed to this article:

Dell Computer…………………………(512) 338-4400

Instrument Specialties……………… (714) 579-7100

Product Safety Consulting………… (630) 238-0188

Qualified Specialists………………… (281) 448-5622

TUV Rheinland of North America……(203) 426-0888

Table 1

Copyright 1998 Nelson Publishing Inc.

February 1998