Abstract: A protective device is disclosed having a circuit breaker for an electrical connection between a transformer and a load, wherein an overcurrent device is arranged between the transformer and the load. The overcurrent device has first magnetoelectric transducers arranged at each phase conductor and the neutral conductor, wherein the overcurrent device uses the transducer currents to in each case establish the presence of a first ground-fault current, and wherein the circuit breaker has a switching device, which interrupts at least the phase conductors between the transformer and the load in the event of the presence of a first ground-fault current (unrestricted earth fault).

Abstract: A method is disclosed for controlling an electronic overcurrent trip for low-voltage circuit breakers. According to the method, digitized signals for the electricity values are generated and evaluated, and a tripping device providing short-circuit protection is activated when an overcurrent event is assumed to take place based on the evaluation. According to the method, signals whose electricity value does not lie between the electricity values of the previous signal and the subsequent signal, or whose electricity value does not correspond to the electricity values of the previous signal or the subsequent signal, are rated as potentially erroneous signals and are tested by use of additional criteria.

Abstract: A protective device is disclosed having a circuit breaker for an electrical connection between a transformer and a load, wherein an overcurrent device is arranged between the transformer and the load. The overcurrent device has first magnetoelectric transducers arranged at each phase conductor and the neutral conductor, wherein the overcurrent device uses the transducer currents to in each case establish the presence of a first ground-fault current, and wherein the circuit breaker has a switching device, which interrupts at least the phase conductors between the transformer and the load in the event of the presence of a first ground-fault current (unrestricted earth fault).

Abstract: A three or four pole low-voltage power switch is disclosed wherein the switch is partly provided with a device for detecting ground faults. For this purpose, the current vectorial sum must be produced in the three or four conductors of a monitored network. For the switches of this type, output signals received from Rogowski coils are directed via resistances to an integration capacitor whose voltage forms an input signal of another measuring amplifier representing the current sum of a monitored network. The output signal of the measuring amplifier is, afterwards processed in a known manner in the microprocessor of an excess-current trip.

Abstract: A three or four pole low-voltage power switch is disclosed wherein the switch is partly provided with a device for detecting ground faults. For this purpose, the current vectorial sum must be produced in the three or four conductors of a monitored network. For the switches of this type, output signals received from Rogowski coils are directed via resistances to an integration capacitor whose voltage forms an input signal of another measuring amplifier representing the current sum of a monitored network. The output signal of the measuring amplifier is, afterwards processed in a known manner in the microprocessor of an excess-current trip.

Abstract: A method is disclosed for controlling an electronic overcurrent trip for low-voltage circuit breakers. According to the method, digitized signals for the electricity values are generated and evaluated, and a tripping device providing short-circuit protection is activated when an overcurrent event is assumed to take place based on the evaluation. According to the method, signals whose electricity value does not lie between the electricity values of the previous signal and the subsequent signal, or whose electricity value does not correspond to the electricity values of the previous signal or the subsequent signal, are rated as potentially erroneous signals and are tested by use of additional criteria.

Abstract: An electrical power breaker includes an electronic protective device and an electronic memory. The memory is accommodated in the power breaker such that it is physically separated from said protective device, for operational data for the power breaker. Data security when using the additional electronic memory is increased by the electronic memory being connected to the protective device via a data bus, which can be used to transmit control signals for the purpose of activating or deactivating a write protection device of the electronic memory. The data bus is preferably an I2C bus, and the write protection device is controlled by an I/O module which is likewise controlled by the I2C bus.

Abstract: One problem during the detection of ground faults resides in the fact that the measuring amplifiers have a great amount of tolerance regarding the amplification factor thereof, resulting in a substantial error when errors are handled by means of software. According to the disclosure, the output signals of the measuring amplifiers are summed up phase by phase in a pulse-modulated manner in a summing amplifier. The duration of the pulses generated by the trip are controlled in accordance with the amplification factor of the respective associated measuring amplifier while the output of the summing amplifier represents a ground fault monitoring signal.

Abstract: An electrical power breaker includes an electronic protective device and an electronic memory. The memory is accommodated in the power breaker such that it is physically separated from said protective device, for operational data for the power breaker. Data security when using the additional electronic memory is increased by the electronic memory being connected to the protective device via a data bus, which can be used to transmit control signals for the purpose of activating or deactivating a write protection device of the electronic memory. The data bus is preferably an I2C bus, and the write protection device is controlled by an I/O module which is likewise controlled by the I2C bus.