Circuit-breaker device and method

A circuit-breaker device for protecting a low-voltage electric circuit, the circuit-breaker device comprising:

• a housing having first and second terminals for conductors of the low-voltage circuit;
• a series-connected arrangement of a mechanical break contact unit and an electronic interruption unit, for an electrical connection of said first and second terminals;
• said mechanical break contact unit having contacts and being switchable by opening said contacts for interrupting a current flux or by closing said contacts for conduction of a current flux in the low-voltage circuit;
• said electronic interruption unit having semiconductor-based switching elements and being switchable to a high-resistance state of said switching elements for prevention of a current flux or to a low-resistance state of said switching elements for allowance of a current flux in the low-voltage circuit;
• a current sensor unit for determining a current level in the low-voltage circuit and making instantaneous current values available;
• a control unit connected to said current sensor unit, to said mechanical break contact unit and to said electronic interruption unit, for initiating prevention of a current flux in the low-voltage circuit in an event of overshooting at least one current threshold value;
• and
• the circuit-breaker device being configured to adjust the at least one current threshold value according to a temperature level of the circuit-breaker device;
• the temperature level being converted into a digital temperature value, the digital temperature value being multiplied by a factor, and a resulting product being subtracted from the at least one current threshold value, to obtain an adapted current threshold value.

A circuit-breaker device for protecting a low-voltage electric circuit, the circuit-breaker device comprising:

• a housing having first and second terminals for conductors of the low-voltage circuit;
• a series-connected arrangement of a mechanical break contact unit and an electronic interruption unit, for an electrical connection of said first and second terminals;
• said mechanical break contact unit having contacts and being switchable by opening said contacts for interrupting a current flux or by closing said contacts for conduction of a current flux in the low-voltage circuit;
• said electronic interruption unit having semiconductor-based switching elements and being switchable to a high-resistance state of said switching elements for prevention of a current flux or to a low-resistance state of said switching elements for allowance of a current flux in the low-voltage circuit;
• a current sensor unit for determining a current level in the low-voltage circuit and making instantaneous current values available;
• a control unit connected to said current sensor unit, to said mechanical break contact unit and to said electronic interruption unit, for initiating prevention of a current flux in the low-voltage circuit in an event of overshooting at least one current threshold value;
• and
• the circuit-breaker device being configured to adjust the at least one current threshold value according to a temperature level of the circuit-breaker device;
• the temperature level being converted into a digital temperature value, the digital temperature value being reduced by an offset value, and a result being subtracted from the at least one current threshold value, to obtain an adapted current threshold value.

A circuit-breaker device for protecting a low-voltage electric circuit, the circuit-breaker device comprising:

• a housing having first and second terminals for conductors of the low-voltage circuit;
• a series-connected arrangement of a mechanical break contact unit and an electronic interruption unit, for an electrical connection of said first and second terminals;
• said mechanical break contact unit having contacts and being switchable by opening said contacts for interrupting a current flux or by closing said contacts for conduction of a current flux in the low-voltage circuit;
• said electronic interruption unit having semiconductor-based switching elements and being switchable to a high-resistance state of said switching elements for prevention of a current flux or to a low-resistance state of said switching elements for allowance of a current flux in the low-voltage circuit;
• a current sensor unit for determining a current level in the low-voltage circuit and making instantaneous current values available;
• a control unit connected to said current sensor unit, to said mechanical break contact unit and to said electronic interruption unit, for initiating prevention of a current flux in the low-voltage circuit in an event of overshooting at least one current threshold value;
• the circuit-breaker device being configured to adjust the at least one current threshold value according to a temperature level of the circuit-breaker device;
• a voltage sensor unit for determining a voltage level in the low-voltage circuit and making instantaneous voltage values available;
• periodic instantaneous current threshold values being obtained and being dependent upon a periodic temporal characteristic of instantaneous voltage values;
• and
• instantaneous current values being compared, in a phase-related manner, to the instantaneous current threshold values, for initiating an interruption of the low-voltage circuit in an event of a quantitative overshoot of the value of the instantaneous current threshold value.