优势：
•成本节约解决方案；
•极快速跳闸。
缺点：
•歧视值极低；
•服务质量低，因为至少两个串联断路器必须跳闸。
断路器和开关之间的协调
隔离开关
隔离开关
隔离开关源于相应的断路器
它们保留了外形尺寸、固定系统和
安装为基本版本提供的所有附件。它们是设备
它可以在正常工作条件下接通、携带和断开电流
电路。
它们也可用作子配电盘中的通用断路器、断路器或隔离安装部件，如线路、母线或负载组。
一旦触点断开，这些开关保证隔离，这得益于
它们的触点，其处于适当的距离，以防止电弧冲击
符合有关能力倾向标准的规定
隔离
隔离开关的保护
每个隔离开关应由一个协调装置保护，该装置
防止过电流，通常是一个断路器能够限制
短路电流和允许通过的能量值在可接受的水平
隔离开关。
关于过载保护，断路器的额定电流应为
小于或等于待保护隔离开关的尺寸。
关于SACE Tmax XT和Tmax T系列隔离开关
协调表显示了可保护其免受冲击的断路器
指示的预期短路电流值。
关于Emax系列隔离开关，有必要验证
安装点的短路电流值低于短时
耐受电流I
隔离开关的cw，且峰值低于
闭合电流值（Icm）。

Advantages: • cost-saving solution; • extremely rapid tripping. Disadvantages: • extremely low discrimination values; • low service quality, since at least two circuit-breakers in series have to trip. Coordination between circuit-breaker and switch disconnector The switch disconnector The switch disconnectors derive from the corresponding circuit-breakers, of which they keep the overall dimensions, the fixing systems and the possibility of mounting all the accessories provided for the basic versions. They are devices which can make, carry and break currents under normal service conditions of the circuit. They can also be used as general circuit-breakers in sub-switchboards, as busties, or to isolate installation parts, such as lines, busbars or groups of loads. Once the contacts have opened, these switches guarantee isolation thanks to their contacts, which are at the suitable distance to prevent an arc from striking in compliance with the prescriptions of the standards regarding aptitude to isolation. Protection of switch disconnectors Each switch disconnector shall be protected by a coordinated device which safeguards it against overcurrents, usually a circuit-breaker able to limit the short-circuit current and the let-through energy values at levels acceptable for the switch-disconnector. As regards overload protection, the rated current of the circuit-breaker shall be lower than or equal to the size of the disconnector to be protected. Regarding SACE Tmax XT and Tmax T series switch disconnectors the coordination tables show the circuit-breakers which can protect them against the indicated prospective short-circuit currents values. Regarding Emax series switch disconnectors it is necessary to verify that the short-circuit current value at the installation point is lower than the short-time withstand current I cw of the disconnector, and that the peak value is lower than the making current value (Icm).