A protective circuit device, the photovoltaic system and method for operating such a

The invention relates to a protective circuit device (10) of a photovoltaic system (1), the interconnected a plurality of on strings (4) and via a connection line (9) with an inverter (7) comprises solar modules (3) connected with an on the connection cable of the solar modules parallel bypass line (11), a first switching element (13; 13a '; 13a' ') for active switching of the connection line or the bypass line, an associated at least one solar module or string and a second switching element (' 13b;; 13b '13b') sensor element (15; 15a '; 15b') for sensing the operating state of the solar module or solar modules characterizing physical size and a sensor signal input to the sensor element and the output side connected via a control signal connection with the first and second switching element switch control unit (16; 17; 17 ) for actuating the first or the second switching element in response to upon sensing determined value of the operating state characteristic value. Furthermore, it relates to a photovoltaic system having such a protective circuit device and a method of operating such.