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    The history of Square D

    In 2003, the Square D by Schneider Electric brand celebrated one hundred years of know-how and innovation in electricity and automation management.

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Products and systems developed by the Square D brand are present in all sectors of activity, from circuit breakers to monitoring and control systems. The tertiary and residential building sectors are major consumers of its products.

Milestone Dates

  • 1902 Detroit Fuse and Manufacturing, a US supplier of electrical distribution and industrial control equipment, begins operations.
  • 1917 The company changes its name to Square D, based on its trademark "D" appearing on conduit boxes and switches.
  • 1926 Square D builds its first power distribution panelboard. Three years later it moves into the industrial controls market.
  • 1935 The company launches its own range of circuit breakers and the first circuit breaker for residential use.
  • 1940s Square D has 10 factories in North America, 43 regional offices and a workforce of 7000, manufacturing half of all the circuit breakers used in aviation.
  • 1950s The company opens its first European subsidiary and introduces its iconic QO circuit breakers.
  • 1970s Square D opens agencies in South Africa and Asia. It introduces the Symax PLC and Watchdog energy management system.
  • 1980s After many years of growth and expansion, Square D focuses on electronics, through strategic acquisitions.
  • 1991 Square D has 18,500 employees and operations in 23 countries when it joins Schneider Electric.

Schneider Electric history

Learn about our history and discover other brands that are part of Schneider Electric today.
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