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

在这一方面还是塑壳断路器更加突出，其在设置的灵 活性上比微型断路器更好。塑壳断路器的过流和短路保护装置是各自独 立的，使用中过流保护的动作值还可以做出灵活调整。微型断路器的过流保护和短路保护是统一装置，调节灵活 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.

根据以上的情况看似乎都是微型断路器处于下风，但其实对于某些时候，还是需要选择微型断路器的。比方说需要提高线路的安 全性时，因为微型断路器的动作灵敏度高，分断动作快，更有利于对线路及电器的保护。

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。塑壳断路器对过流和短路采用两套装置分别保护，过流保护动作值可以人工调整，方便迅速。而微型断路器对过流和短路共用一套装置，电流不可调，导致很多时候无法解决问题。塑壳断路器相间距离大，且有灭弧罩，灭弧能力强，能承受更大的短路电流，且不易引发相间短路，从而使用寿命也比微型断路器校长。

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.

由此可以看见两者都有着各自的优点和适合使用的地方，关键是要充分了解塑壳断路器和微型断路器的区别，并根据自身的需要进行选择。

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.