Abstract: A current measurement apparatus for measurement value acquisition includes: a current sensor; and a current measurement transducer. A measurement range of the current sensor is adjustable. The current sensor includes at least one magnetic field sensor having at least one matching circuit and a memory. The current measurement transducer includes an input interface for inputting and/or a communication interface for transmitting information with respect to measurement range switching. The current measurement transducer includes an output interface for outputting the measurement values. The measurement range switching for the current sensor is based on the matching circuit accessing at least one new matching value in the memory, by which a change of the measurement signal of the magnetic field sensor is adjustable.

Abstract: A monitoring device for an ungrounded electric network of a photovoltaic system. The monitoring device includes a short circuit measuring circuit having a first electric measuring circuit conductor connecting a first electric pole of the photovoltaic system with a reference point by means of at least one protective component, and second electric measuring circuit conductor for connecting a second electric pole of the photovoltaic system with ground be means of at least one protective component. A first component is connected between one of the measuring circuit conductors and ground, and a measuring device for measuring an electric parameter of the first component, wherein a non-zero value of the parameter and/or a change of the value of the parameter indicate an electric fault between the photovoltaic system and ground.

Abstract: A monitoring device for an ungrounded electric network of a photovoltaic system. The monitoring device includes a short circuit measuring circuit having a first electric measuring circuit conductor connecting a first electric pole of the photovoltaic system with a reference point by means of at least one protective component, and second electric measuring circuit conductor for connecting a second electric pole of the photovoltaic system with ground be means of at least one protective component. A first component is connected between one of the measuring circuit conductors and ground, and a measuring device for measuring an electric parameter of the first component, wherein a non-zero value of the parameter and/or a change of the value of the parameter indicate an electric fault between the photovoltaic system and ground.