Moulded case circuit breaker (MCCB) is widely used as a kind of circuit breaker like frame circuit breaker. So what are the differences between these two kinds of circuit breakers in the process of practical application? Here is a brief analysis of ABB moulded case circuit breaker agent introduced to switch factory for us.

1.塑殼斷路器采用的是塑料化結構，它的特點是斷路器外殼和框架都采用的是塑料壓制而成，并且它將觸頭、滅弧系統等都放在了一個絕緣小室中，以防止其之間發生短路，并為了確保電弧能夠向上噴出，保證了觸頭系統可靠分斷。而框架斷路器采用的則是模塊化結構，它分為框架、觸頭滅弧系統、手動操作機構、電動操作機構、智能型 控 制器以及抽屜座等結構。并且其每個部分均可成為一個完整獨 立的部件，組裝時只需1-2個螺釘即可將其固定，拆裝也十分方便，便于其檢修維護。

1. The moulded case circuit breaker adopts the plastic structure, which is characterized by that the shell and frame of the circuit breaker are made of plastic pressing, and it places the contact and arc extinguishing system in an insulated chamber to prevent short circuit between them, and ensures the reliable breaking of the contact system in order to ensure that the arc can be ejected upward. The frame circuit breaker adopts modular structure, which is divided into frame, contact arc extinguishing system, manual operation mechanism, electric operation mechanism, intelligent controller and drawer base. And each part can be a complete and independent component, which can be fixed with only 1-2 screws during assembly. It is also very convenient for disassembly and assembly, and convenient for maintenance.

2.塑殼斷路器的產品種類繁多，其特點是結構緊湊，操作容易，其結構與功能也比較簡單。而框架斷路器則功能完善，特別是近年來的單片機技術的廣泛應用，從而使框架斷路器逐步朝著高性能、易維護、網絡化的方向發展。

2. There are many kinds of moulded case circuit breakers, which are characterized by compact structure, easy operation, and simple structure and function. The frame circuit breaker has perfect functions, especially the wide application of MCU technology in recent years, which makes the frame circuit breaker gradually develop in the direction of high performance, easy maintenance and networking.

3.在額定電流上，塑殼斷路器一般為630A以下，而框架斷路器的額定電流要大很多，一般為630A-6300A。

3. In terms of rated current, moulded case circuit breaker is generally less than 630A, while the rated current of frame circuit breaker is much larger, generally 630a-6300a.

4.而在分段能力上，框架斷路器要比塑殼斷路器高。一般情況下，800A以上的回路或分段能力要求比較高的回路大多采用的是框架斷路器，而630A以下的回路，則一般使用塑殼斷路器。

4. In terms of sectional capacity, the frame circuit breaker is higher than the moulded case circuit breaker. Generally speaking, the circuit with more than 800A or the circuit with higher requirements for sectional capacity is mostly frame circuit breaker, while the circuit with less than 630A is generally molded case circuit breaker.

5.框架斷路器的所有零件都裝在一個絕緣的金屬框架內，常為開啟式，可裝設多種附件，其更換觸頭和部件也較為方便，多用在電源端總開關。而塑殼斷路器的接地線端子外觸頭、滅弧室、脫扣器和操作機構等都被裝在了一個塑料外殼內，一般情況下我們不考慮其維修，它比較適用于作支路的保護開關，其大部分采用的是手動操作。

5. All parts of the frame circuit breaker are installed in an insulated metal frame, which is usually open type. It can be equipped with a variety of accessories, and it is more convenient to replace contacts and components. It is often used in the main switch of the power end. The external contact of ground wire terminal, arc extinguishing chamber, release and operating mechanism of MCCB are all installed in a plastic shell. Generally, we do not consider its maintenance. It is more suitable for branch protection switch, and most of them are operated manually.