LZR.MAR–LZR Electronics–sc– — –##
Walking through the maze of international safety approvals
The unification of standards is beginning to ease the approval process for power supplies and other equipment
BY RAMI R. LOYA
LZR Electronics
Gaithersburg, MD
Like other electronic products, power supplies have traditionally faced a maze of international safety approvals in both North America and Europe. Fortunately, this maze is gradually being solved by harmonizing standards. This is happening on two fronts. The International Electrotechnical Commission (IEC) is unifying standards within the countries of the European community. In North America, Underwriters Laboratories (UL) and the Canadian Standard Association (CSA) are unifying their standards.
This unification has almost eliminated the need to comply with each country's individual safety standards. Instead, manufacturers now need only comply with a harmonized standard that is accepted by most of the European and North American countries with some specific minor deviations for each country where applicable. Certification procedures have also been simplified. The table on page 42 lists the safety and EMI standards by industry and major market center.
The CB scheme
A breakthrough in expediting the approval of international safety standards is the Certification Body (CB) scheme established by the IEC. The program is called the IEC System for Conformity Testing to Standards for Safety of Electrical Equipment. The IEC operates the CB scheme for the mutual acceptance of product safety test results by 30 countries worldwide. See page 41 for a list of participating countries.
In the CB scheme, a manufacturer submits a product for testing with its local National Certification Body (NCB), which is accredited by the IEC as a participant (for example, UL, CSA, and VDE). The test results from the local NCB are used for issuing a CB Test Certificate and a CB Test Report. Armed with these documents, manufacturers can obtain certification from 30 countries that are participating in the scheme without additional testing. Manufacturers can now present these two documents to the NCB in the country where they are seeking approval.
The local NCB will examine the CB documents and product samples if necessary. If it finds all the information satisfactory, the local NCB will grant their safety approval without further testing. Figure 1 shows the CB scheme flowchart.
After the approval is granted, the manufacturer has to follow all the procedures conforming to continued use of the NCB's certification mark, including factory audits and product inspections.
Notified Body Report
Another method for cost-effective safety agency approval in European Common Market (EC) countries is called the Notified Body Report (NBR). Laboratories accredited by the National Measurement Accreditation Service (NAMAS) can issue this report, which documents third-party evaluation of a product's compliance with the applicable European standard. With this single report, a manufacturer or its local agents can complete a Declaration of Conformity stating its product's compliance. This report is accepted by a wide range of EC regulatory bodies, which will grant the manufacturer the desired safety mark.
U.S. manufacturers can also obtain certification in EC countries using the NBR. The manufacturers can work with U.S.-based ETL testing labs, which will perform the tests and issue a NBR through its ETL Albury Lab in the U.K. This report in turn will allow them to obtain the safety marks required for all EC countries. Figure 2 illustrates the process of obtaining International Safety Approvals.
North American agency certification
For many years, only UL and CSA could certify manufacturers in North America. However, legislative changes allowed other testing companies to compete in the market. Approval by an Occupational Safety and Health Administration (OSHA) accredited lab, per OSHA Section 1910.339, is now all that is required. The OSHA standard states electronic equipment is acceptable if it is listed by a Nationally Recognized Testing Laboratory (NRTL).
In the past, UL was the only OSHA-approved test agency. Now other select labs, such as ETL, have been accredited by OSHA as NRTL with the authority to issue safety approvals. Also, the CSA can provide NRTL approval and others. These labs can test and certify products to UL or ANSI standards. Of course, they cannot issue the UL mark. Instead, they issue NRTL or ETL marks, which meet the full legal requirements prescribed by OSHA.
On the Canadian front, UL has now been accredited by all Canadian provinces except Quebec as a Recognized Test Laboratory. (Quebec's approval of UL is imminent.) UL will test products to the Canadian standard requirements and provide the manufacturer with a C-UL mark, which will be accepted in Canada. This enables North American applicants to either apply to UL to obtain both the UL and C-UL marks or apply to CSA to obtain the CSA and NRTL marks. Alternatively, they can apply for ETL and obtain the ETL and NRTL marks.
When applying for the certification with one of these agencies, a manufacturer should keep in mind its own global certification needs and the agency's participation in the CB scheme so it can obtain the rest of the needed approvals. Most manufacturers will find it quicker and more cost effective to use the services of an independent test laboratory that can do all the product testing and paperwork and have it periodically audited by test engineers of the NCBs they cooperate with. Such independent laboratories (see box, “Independent test laboratories”) are familiar with the standards and the approval process. All the manufacturer has to do is supply them with samples and technical data and then pay the associated fees.
FCC Part 15
Part 15 of the Federal Communications Commission (FCC) regulates the limits on the amount of electromagnetic interference (EMI) that can be emitted from a wide range of electronic devices. It requires compliance with either Class A requirements, which cover digital equipment sold to businesses (office, industry, etc.), or the more stringent Class B requirements that govern products sold to consumers.
Products like power supplies can be tested to verify EMI compliance using resistive loads but cannot be certified independently because they are a subsystem and only operate when connected to a product. In such cases, the testing and certification process is performed on a system that contains the product itself, the power supply, and other peripheral equipment. The whole system is tested under operating conditions to verify compliance. Certified devices must undergo a more elaborate process by which they have to submit test data and samples if necessary to the FCC for verification and final certification. The independent labs mentioned on page 44 can assist users in complying with this spec.
FCC Part 68
A federal regulation, FCC Part 68 requires every device that connects to the nations telephone network to be tested and registered before it can be connected to the network. The tests determine if the new device has the potential to cause any operational problems or interference with the normal operations of the network. This legislation applies mostly to the telephone and telecomunication industries (phones, modems, LANs, multiplexers, fax machines, etc.) Test data are compiled by the test lab and submitted to the FCC for final approval and issuance of a registration number. The FCC registration number is the proof for compliance and has to be included on the product label.
The CE mark–EMC directive
Part of the standard harmonization process in Europe includes electromagnetic compatibility (EMC, or CE) directive, which is uniform for the European community. As long as a European or international manufacturer meets this requirement, its products can be sold freely in Europe. Directive 89/336/EEC, which guides EMC, states two main objectives: (1) devices should not emit in a manner which will interfere with other devices and (2) devices should be immune to outside noise.
As of Jan. 1, 1996, all devices sold in the EC must be certified to conform to the EMC standards and their products must have the CE marks. Manufacturers can comply with the EMC directive through self-certification by making a Declaration of Conformity supported by test data from an independent lab. Alternatively, a notified laboratory in Europe can be used to obtain certification.
The EC telecom directive
EC Directive 91/263/EEC broadly defines the Telecom Network to include: wire, optical and radio communications. It requires telecom equipment to meet safety, EMC, and telecom standards to avoid creating problems in the telecom network. The European Telecomunications Standards Institute (ETSI) is in the process of preparing standards called NETS. Currently, each country requires its own approval for telecom products.
The British Approval Board for Telecomunication (BABT) has the most widely accepted standards, which are very similar to the ones being adopted by ETSI. Manufacturers who want to sell telecom products in Europe should conform to the BABT standards to simplify the approval process in the future. BABT approval requires that not only the products have to comply, but also the manufacturing facility where the products are made. Applications for BABT approvals can be filed by companies within EC member countries serving as the applicant or agent, while the manufacturer can be outside the EC.
CAPTIONS:
Fig. 1. The CB scheme simplifies the process of getting international safety approvals in several countries.
Fig. 2. This flowchart outlines the steps to obtain international safety approvals.
Box:
Independent Test Laboratories
Product Safety Engineering
Tampa, FL
Dale Burns 813-989-2360
Dash, Straus, & Goodhue/Inchcape Testing Services
Boxborough, MA
William O'Brien 508-263-2662
Product Safety Engineering
Irvine, CA
Steve Watkins 714-453-8311
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