Standard for industrial plugs and sockets
1、 International standards
Developed industrial countries in Europe and America have conducted research, development, and production of industrial plugs and sockets earlier. Since the 1970s, Europe has implemented safety certification for electrical products and developed a set of industrial plug and socket safety standards CEE 17. After 1979, the International Electrotechnical Commission (IEC) officially issued IEC 309-1:1979 (Industrial plugs, sockets and couplers Part 1: General requirements) and IEC 309-2:1981 (Industrial plugs, sockets and couplers Part 2: Dimensional interchangeability requirements for electrical accessories with pins and sockets), becoming the first international standard for industrial plugs and sockets.
Secondly, the IEC309 standard has been revised three times. In February 1999, the International Electrotechnical Commission (IEC) released its fourth edition, namely IEC 60309-1/2. The standard number has been uniformly increased from three digits to five digits, and this version integrates the technical changes of IEC 309-1 2nd and 3rd editions, becoming the latest version of the standard.
2、 National standards
In the early stages of reform and opening up in the 1980s, the equipment introduced was equipped with industrial plugs and sockets that used the international standards of IEC 309-1 and 2. At that time, there was no national standard in China that was in line with the international standard, and such products were not produced domestically and were very scarce in the market. This not only affects the use of imported equipment, but also hinders the design, manufacturing, and export of equipment in our country. Therefore, it is imperative to develop corresponding national standards based on IEC international standards. On December 21, 1989, the National Bureau of Technical Supervision officially issued the GB/T 11918-11919-1989 (Industrial Plug, Socket and Coupler) national standard, which was implemented on July 1, 1990. This standard is equivalent to IEC 309-1 and 2.
In order to meet the needs of economic and technological development and align with international standards IEC 60309-1,2, China has revised the 1989 version of the standard. On November 2, 2001, the General Administration of Quality Supervision, Inspection and Quarantine of China issued a new version of the national standard GB/T 11918-11919-2001 (Industrial Plug, Socket and Coupler), which was implemented on June 1, 2002. It is equivalent to IEC 60309-1 and 2, with a wide and more comprehensive applicability, further improving the safety and quality of the product, and is internationally recognized to meet domestic and international needs.