With the use of plastic case circuit breakers more and more widely, the requirements for circuit breakers are also higher and higher. In order to save space and achieve beautiful effect, the volume of circuit breaker is smaller and smaller, but the function is more and more powerful. Molded case circuit breaker is developing towards large current and small volume.

Plastic case circuit breaker is developing toward small volume. Specific manifestations are as follows: the exchange of energy storage type operation and manual operation mechanism reduces obviously the thickness of live operation mechanism products, reduces the thickness of distribution cabinet, improves the short circuit breaking index, basically matches the high breaking index of double breakpoint products, and improves the short endurance index and selective release reliability.

Nowadays, plastic case circuit breakers with small volume and high cost performance have appeared in the market. This kind of circuit breakers saves the production cost, reduces the thickness of products and enlarges the scope of use. In addition, the number of parts is reduced and the shape is simplified so that it can be semi-automated mass production.

With the improvement of production technology, the rated current range of plastic case circuit breaker is becoming larger and larger, the range of rated large current is getting larger and larger, and the range of rated small current is getting smaller and smaller. There are already 0.1-25A products on the market. Technical indicators are becoming more and more advanced, and all kinds of performances have been improved, especially the seismic performance. In the process of researcher's development, the product structure is becoming more modular, miniaturized, integrated, compact, flexible and convenient to assemble. In addition, the product can also install soft starter, intelligent detector and so on.

Like the universal circuit breaker ACB, the performance of DC products, distributed photovoltaic grid-connected products and reclosing leakage circuit breakers are further improved. The working voltage of DC derivative products has been increased to 1000V or even higher, which can be used in photovoltaic power generation, electric vehicle charging equipment, emergency power supply and other occasions; the precision of thermal magnetic protection has also been improved; disconnector can be used in AC and DC. Derived distributed photovoltaic grid-connected products tend to improve the ability to withstand damp and heat, salt spray, ultraviolet radiation and other harsh environments, enhance the strength and corrosion resistance of key components, improve the reliability of mechanisms and conductive systems, and the minimum adjustment step can be less than or equal to 1S. Derived reclosure leakage circuit breakers have wider application scope, for example, they can be used in rural power network transformation.

Of course, the trend performance of plastic case circuit breaker also needs related technologies to achieve, such as contact arc extinguishing system technology; fully selective coordination technology; DC critical current interruption technology; high-precision miniaturized mutual inductance technology; modular technology of motor protection circuit breaker mechanism; industrial production technology; DC current detection and protection technology; conductive circuit heating and heat dissipation technology.

Plastic case circuit breaker is one of the important products in low voltage industrial appliances. The improvement and improvement of its performance will further guarantee the safety of power workers and help to reduce power accidents.