本发明涉及一种开关，用于保护电气电路具有： - 用于中断电气电路的跳闸装置（AE）， - 用零序电流互感器（ZCT），通过电路的导体被引导，用于检测差分电流并具有第一线圈 其中一个差动电流是可移除的， - 用于检测所述电路的电流值的电流传感器（分流器）， - 用于检测电路的电压值的电压传感器; - 一个测试按钮（T）， - 用电弧故障模拟单元（LPGA） 具有一个输入和两个输出， - 微处理器（MCU），其被连接到所述测试按钮，电流传感器，电压传感器，所述第一绕组的总和电流转换器的，电弧故障模拟单元和输入端的跳闸机构，并且被设计为使得 如果某些圣 当由所述触发电路的故障电弧中断装置romgrenzwerte或制成，该总和电流互感器具有第二绕组（NT），这是直接或经由连接到微处理器的第一电阻器（RT），所述电弧故障模拟单元的输出的信号 可以通过测试信号将电流和/或电压值提供给微处理器。

The invention relates to a switch to protect an electrical circuit:
- with a triggering device (AE) for interrupting the electrical circuit,
- with a summation current transformer (ZCT), are guided through the conductor of the electric circuit for detecting differential currents and having a first winding to which a differential current is removable,
- with a current sensor (shunt) for detecting current values ​​of the electric circuit,
- a voltage sensor for detecting voltage values ​​of the electrical circuit,
- with a test key (T),
- with an arc fault simulation unit (LPGA), having an input and two outputs,
- a microprocessor (MCU), which is connected to the test button, the current sensor, the voltage sensor, the first winding of the summation current converter, the input of the arc fault simulation unit and the tripping mechanism, and is configured such that beyond certain power limits, or in the presence of a fault arc, an interruption of the electrical circuit by the trigger means,
wherein the summation current transformer has a second winding (NT) which is directly or via a first resistor (RT) connected to the microprocessor,
wherein the signals of the outputs of the arc fault simulation unit instead of the current or / and voltage values ​​are fed to the microprocessor by a test signal.