IEC 60950

IEC 60950 is a foundational international safety standard developed by the International Electrotechnical Commission for information and communication technology equipment. It established essential safety requirements to protect users and service personnel from hazards such as electric shock, fire, and mechanical injury. The standard was widely adopted and harmonized under regional frameworks like the European Union's Low Voltage Directive, forming the basis for national variants such as UL 60950-1 in North America and EN 60950-1 in Europe. Its principles have been succeeded by the hazard-based safety engineering approach of IEC 62368-1.

Scope and purpose

The primary scope of this standard encompassed a broad range of information technology equipment and telecommunications network equipment designed for use in office, home, and similar environments. Its fundamental purpose was to ensure the safety of end-users, maintenance personnel, and service providers by mitigating risks associated with installation and operation. The document covered equipment powered from mains supplies, batteries, or telecommunication circuits. It specifically aimed to prevent injury from electrical shocks, excessive temperatures, radiation, and chemical hazards as outlined by organizations like the International Organization for Standardization.

Key requirements and safety principles

Key requirements were built upon established safety principles involving insulation, creepage distances, and protective earthing. The standard mandated protection against access to hazardous live parts through the use of basic, supplementary, or double insulation systems. It set strict limits on accessible parts for touch currents and introduced safeguards against fire spread from internal overcurrents or component failures. Requirements also addressed the safety of batteries, particularly concerning overheating and venting, and set guidelines for mechanical stability and enclosure strength to prevent injury.

Equipment categories and classifications

Equipment was classified according to its method of power connection, such as pluggable or permanently connected types, and by its portability. A critical classification distinguished between Class I equipment, which relies on a protective earth connection, and Class II equipment, which depends entirely on double or reinforced insulation. Further categories defined equipment for use in telecommunications networks, which had specific requirements for overvoltage protection and isolation from the Public switched telephone network. Equipment intended for restricted access locations, like data centers, had different accessibility criteria than products for general use by the public.

Testing and compliance procedures

Compliance was demonstrated through a combination of type tests, routine production tests, and assessment of constructional criteria. Testing laboratories, such as those accredited by the International Laboratory Accreditation Cooperation, performed rigorous evaluations for dielectric withstand, leakage current measurement, and abnormal operation under fault conditions. Procedures included ball pressure tests for fire enclosure materials, stability tests, and assessments of overcurrent protection devices. Manufacturers typically engaged with Nationally Recognized Testing Laboratories like Underwriters Laboratories or Intertek to obtain certification marks, which were often required for market access in regions like the United States or the European Economic Area.

Relationship to other standards

This standard had a direct and harmonized relationship with many regional and national standards. In the European Union, it was published as EN 60950-1 and was a harmonized standard under the Low Voltage Directive, providing a presumption of conformity. In the United States and Canada, it was aligned with UL 60950-1 and CSA C22.2 No. 60950-1, respectively. It was closely related to the IEC 60065 standard for audio/video equipment and shared foundational safety concepts with the IEC 60601 series for medical electrical equipment. The standard also referenced numerous other International Electrotechnical Commission documents for specific component requirements, such as those for fuses, transformers, and optocouplers.

Historical development and withdrawal

The standard was first published in 1985, consolidating earlier safety requirements for the growing information technology industry. It underwent multiple amendments and editions, with the second edition in 1999 and a consolidated third edition in 2005, to address evolving technologies like Voice over IP equipment and Power over Ethernet. The final major revision was published in 2013. Its development was formally concluded with the publication of IEC 62368-1, a hazard-based standard covering both audio/video and information technology equipment. The International Electrotechnical Commission officially withdrew it in December 2020, establishing a transition period during which certifications to the old standard remained valid in markets like the European Union until the end of 2024.