有关断路设备中英对照.doc

断路设备断路设备在电力系统中有许多形式，通过小电键开关(在落地灯和引出线中)操作巨大的断路器以控制电能在高压网络中的通道。断路设备一般有三种基本类型。开关是用来闭合，断开或者改变电路连接方式的设备。这个定义意味着开关是用于系统的正常运行操作的。断路器是在正常或异常条件下断开电路可分离触点的设备。要求断路器动作的异常条件主要是在短路时断路器应该经得起持续时间短，但幅值大的电流，并在必要时断开电路。熔断器是过电流保护装置，它具有一个易熔的元件可由于过电流而受热熔化烧断，从而断开电路。熔断器一般多用在进线口盒中，用来保护主线路和入户的每一个独立电路。熔断器也可用在配电网的许多一次线路中，在少数情况下，也用于大功率容量的高压设备。直流电路中的断路器只要依靠拉长电弧来达到游离作用。用于低压交流回路的断路器，由于在过零换向电压不能满足再次阴极放电起弧的需要，因此具有容易灭弧的优点。用于中压交流回路中的断路器，利用阴极辉点现象的方法和拉长电弧去游离的方法相结合。用于高压回路中的断路器，电弧被拉长，并迫使它接触油的表面，并依靠产生的油雾或气体射流制冷。circuit-interrupting devices cricuuit-interrupting devices in power systems are of many forms， ranging from the small key switcher(in flool lamps and extension cords) to the enormous circuit breakers that control the flow of power in the high-voltage networks.three basic types of circuit-interrupting device are recognized.a swich is a device for making， breaking， or changing the connection in an electric circuit.this definition implies that the switch is used in a system in its normal operating condition.a circuit breaker is a devices for interrupting a circuit between separable cintacts under normal or abnormal conditions.the abnormal conditions during which a circuit breaker may be asked to operate are primarily those which exist during short circuit.the circuit breaker is designed to withstand these short-duration，high-magnitude currents and to interrupt them if necessary.a fuse is an over current protective device with a circuit-opening fusible member directly heated and destroyed by the passage of over current through it.probably the most common application is in the service entrance boxes of residence， where fuse may be used to protect the main lines and each of the several individual circuits into the house.fuse are also used in many applications on distribution primary circuits and to a limited extent on bulk power high-voltage equipment.breakers for dc circuits rely principally on lengthening of the arc and subjecting it to demonizing effects.in breakers for operation in low-voltage ac circuits，advantage is taken of the voltage required to establish a cathode spot.in breakers for medium-voltage ac circuits，the cathode-spot phenomena may be combined with methods for bringing about the lengthening and deionization of the arc path.in breakers fo