Transformer Design for ROHS Compliance

Transformer manufacturers and the designers of electronic equipment continue to face technology and manufacturing challenges in the design of their respective products to meet the European Union’s (EU) Directive 2002/95 entitled, “Restrictions On The Use of Hazardous Substances (RoHS).The EU’s RoHS directive restricts the use of mercury, lead, hexavalent chromium, cadmium and a range of flame retardants, notably polybrominated biphenyls and polybrominated diphenyl ethers. While there are a number of exemptions to RoHS requirements, the directive applies to the producers and importers of electrical and electronic equipment in Europe. The involvement of the EU has made RoHS a defacto global standard for nearly all transformer manufacturers.

RoHS requires that products placed on the market must not contain the restricted hazardous substances at levels above the maximum concentration limit. Manufacturers must prepare documentation to show their products are compliant and make themselves available for audit if requested. The documentation also must be maintained for four years after the product is no longer sold in the marketplace. ■