The main definitions regarding LV switchgear and controlgear are included in the international Standards IEC 60947-1, IEC 60947-2 and IEC 60947-3. Main characteristics Circuit-breaker A mechanical switching device, capable of making, carrying and breaking currents under normal circuit conditions and also making, carrying for a specified time and breaking currents under specified abnormal circuit conditions such as those of short-circuit. Current-limiting circuit-breaker A circuit-breaker with a break-time short enough to prevent the short-circuit current reaching its otherwise attainable peak value. Plug-in circuit-breaker A circuit-breaker which, in addition to its interrupting contacts, has a set of contacts which enable the circuit-breaker to be removed. Withdrawable circuit-breaker A circuit-breaker which, in addition to its interrupting contacts, has a set of isolating contacts which enable the circuit-breaker to be disconnected from the main circuit, in the withdrawn position, to achieve an isolating distance in accordance with specified requirements. Moulded-case circuit-breaker A circuit-breaker having a supporting housing of moulded insulating material forming an integral part of the circuit-breaker. Disconnector A mechanical switching device which, in the open position, complies with the requirements specified for the isolating function. Release A device, mechanically connected to a mechanical switching device, which releases the holding means and permits the opening or the closing of the switching device. 1

低压开关设备和控制设备的主要定义包含在
国际标准IEC 60947-1、IEC 60947-2和IEC 60947-3。
主要特征
断路器
一种机械开关装置，能够在正常电路条件下接通、承载和断开电流，并且能够接通、承载指定的电流
特定异常电路条件下的时间和开断电流，如
就像那些短路。
限流断路器
断路器，其断开时间短到足以防止短路
电流达到本可达到的峰值。
插入式断路器
一种断路器，除了其断开触点外，还具有一组
使断路器能够拆除的触点。
抽出式断路器
一种断路器，除了其断开触点外，还具有一组
使断路器能够与电源断开的隔离触点
主电路处于抽出位置，以在中实现隔离距离
按照规定的要求。
塑壳断路器
一种具有模制绝缘材料支撑外壳的断路器
构成断路器不可分割的一部分。
隔离开关
机械开关装置，其在打开位置符合
隔离功能规定的要求。
释放
与机械开关装置机械连接的装置，其
释放保持装置，并允许打开或关闭
开关设备。
1.