The main function of MCCB is to provide protection for overload and short circuit in low voltage distribution system and motor protection circuit. Because of its reliability and stability, it has been widely used in industry. Miniature circuit breaker (MCB) is also used in a wide range and a large number of circuit breaker products, the main function is to provide protection for the building electrical terminal distribution device. Because both of them belong to circuit breaker, and molded case circuit breaker is mostly used for small capacity on-off, it is very practical and important to understand the difference between the two and choose the right product

在這一方面還是塑殼斷路器更加突出，其在設置的靈 活性上比微型斷路器更好。塑殼斷路器的過流和短路保護裝置是各自獨 立的，使用中過流保護的動作值還可以做出靈活調整。微型斷路器的過流保護和短路保護是統一裝置，調節靈活 性上存在一定不足。

In this aspect, MCCB is more prominent, and its setting flexibility is better than MCB. The over-current and short-circuit protection devices of MCCB are independent, and the action value of over-current protection can be adjusted flexibly. The over-current protection and short-circuit protection of miniature circuit breaker are unified devices, and there are some shortcomings in regulation flexibility.

根據以上的情況看似乎都是微型斷路器處于下風，但其實對于某些時候，還是需要選擇微型斷路器的。比方說需要提高線路的安 全性時，因為微型斷路器的動作靈敏度高，分斷動作快，更有利于對線路及電器的保護。

According to the above situation, it seems that the miniature circuit breaker is at a disadvantage, but in fact, for some times, it is still necessary to choose the miniature circuit breaker. For example, when we need to improve the safety of the line, because the micro circuit breaker has high sensitivity and fast breaking action, it is more conducive to the protection of the line and electrical appliances.

操作上看。塑殼斷路器對過流和短路采用兩套裝置分別保護，過流保護動作值可以人工調整，方便迅速。而微型斷路器對過流和短路共用一套裝置，電流不可調，導致很多時候無法解決問題。塑殼斷路器相間距離大，且有滅弧罩，滅弧能力強，能承受更大的短路電流，且不易引發相間短路，從而使用壽命也比微型斷路器校長。

In terms of operation. Moulded case circuit breaker adopts two sets of devices to protect over-current and short circuit respectively. The action value of over-current protection can be adjusted manually, which is convenient and rapid. The miniature circuit breaker shares a set of device for over-current and short circuit, and the current is not adjustable, which leads to many problems that can not be solved. Moulded case circuit breaker has large phase to phase distance, and has arc extinguishing cover, strong arc extinguishing ability, can withstand larger short circuit current, and is not easy to cause phase to phase short circuit, so its service life is longer than that of miniature circuit breaker.

由此可以看見兩者都有著各自的優點和適合使用的地方，關鍵是要充分了解塑殼斷路器和微型斷路器的區別，并根據自身的需要進行選擇。

It can be seen that both of them have their own advantages and are suitable for use. The key is to fully understand the difference between MCCB and MCB, and choose according to their own needs.