1.空气开关也就是空气断路器，是与塑壳式断路器相对的，它在电路中的作用是接通、分断和承载额定工作电流和短路、过载等故障电流，并能在线路和负载发生过载、短路、欠压等问题下，迅速分断电路，对电路进行可靠的保护。 1. The air switch which is air circuit breaker, as opposed to a molded case circuit breaker, its role in the circuit is connected, breaking and carrying the rated working current and short circuit fault current, overload, etc, and can be in the line and load problem such as overload, short circuit, undervoltage, breaking circuit quickly, for reliable protection circuit. 2.塑壳断路器能够自动切断电流，一般情况下，在电流超过设定后，就会自动触发保护。塑壳在这里说的是用塑料绝缘体来作为装置的外壳，用来隔离导体之间以及接地金属部分。塑壳断路器里面通常含有热磁跳脱单元，同时大型号的塑壳断路器则会配备固态跳脱传感器。 The molded case circuit breaker is able to automatically turn off the current, and normally when the current exceeds the set, the protection is triggered automatically. In this case, the plastic insulator is used as the casing of the device, which is used to separate the conductor and the ground metal parts. The plastic case breaker usually contains a thermal magnetic jump off unit, while the large plastic case breaker will be equipped with a solid-state jumping sensor. 简单的说，就是断路器一种开关装置，可以将它简单的想象为电灯开关。但断路器开关比电灯开关复杂得多，其中包含了诸多保护装置。 Simply put, the circuit breaker is a switch device that can simply imagine it as a light switch. But circuit breaker switches are much more complex than light switches, including many protective devices. 但不论断路器的内部多么复杂，都不影响它是一个开关的本质。故而在某些场合，可以直接将“断路器”称为“开关”。 But no matter how complicated the circuit breaker is, it doesn't affect the nature of a switch. In some cases, the "circuit breaker" can be called "switch" directly. 断路器下还有分类，例如根据电压分类可以分为低压断路器和高压断路器；根据极数分类可以分为一极、二极、三极、四极等。 There are also categories under the circuit breaker, for example under voltage classification which can be classified as low voltage circuit breaker and high voltage circuit breaker. According to the number of poles, it can be divided into one pole, two poles, three poles and four poles. 此外，断路器还可以通过添加附件，使之具有漏电保护、过欠压脱扣等功能。 In addition, the circuit breaker can also be added by adding accessories, such as leakage protection and under-voltage tripping.