The Development History of Miniature Residual Current Circuit Breakers

In 1924, Hugo Stotz and Heinrich Schachtner collaborated to invent the world's first modern miniature circuit breaker using thermomagnetic technology, and obtained a patent.

In China, the first current-operated electronic residual current device (RCD) was developed in the late 1960s (main switch DZS-20). In the mid-to-late 1970s, the DZ15L series electromagnetic RCDs were successfully designed. By the 1980s, models such as DZL16, DZL18, DZL118, DZ12L, DZL33, DZL38, and DZ10L were available, most of which were current-operated electronic (integrated circuit) RCDs. In the mid-1980s, technology from the German company F&G was introduced, leading to the production of FIN type (without overload and short-circuit protection) and FI/LS type (with overload and short-circuit protection) RCDs. In the 1990s, advanced foreign technologies were introduced, leading to the development and production of residual current circuit breakers (RCCBs) such as the VigiC45EIE (electronic), VigiC45ELM (electromagnetic), and VigiNC100.

Modern miniature circuit breakers have not only transformed lifestyles by ensuring residential safety but have also brought electrical safety to all sectors of society, from commercial buildings and factories to railway infrastructure and data centers. Many historical buildings worldwide, such as Kinderdijk in Amsterdam and Aachen Cathedral in Germany, have had their electrical systems upgraded with compact protection devices, such as arc fault detection devices (AFDDs), which integrate residual current and overcurrent protection (RCBO).