Circuit breaker
A circuit breaker for protecting an electric low-voltage circuit has a housing with a grid-side neutral conductor connection, a grid-side phase conductor connection, and a load-side phase conductor connection for the low-voltage circuit. A mechanical isolating contact unit is connected to an electronic interruption unit in series for a phase conductor path and is paired with the load-side phase conductor connection. The electronic interruption unit is paired with the grid-side phase conductor. A current sensor unit ascertains the level of the current of the phase conductor path. A power supply unit is connected or can be connected to the grid-side neutral and phase conductor connections. A control unit is connected to the power supply unit, the current sensor unit, the mechanical isolating contact unit, and the electronic interruption unit. A process for interrupting the current flow in the phase conductor is initiated when current thresholds or current/time thresholds are exceeded.
1 . A circuit breaker device for protecting an electric low-voltage circuit, comprising:
a housing having a grid-side neutral conductor connection, a grid-side phase conductor connection, and a load-side phase conductor connection for the low-voltage circuit;
a mechanical isolating contact unit connected in series with an electronic interruption unit for a phase conductor path, said mechanical isolating contact unit being connected to said load-side phase conductor connection, and said electronic interruption unit being connected to said grid-side phase conductor connection;
a current sensor unit for ascertaining a level of a current of the phase conductor path;
a first voltage sensor unit for ascertaining a level of a voltage across two connections of said electronic interruption unit;
a power supply unit connected, or to be connected, to said grid-side neutral conductor connection and to said grid-side phase conductor connection;
a control unit connected to said power supply unit, to said current sensor unit, to said mechanical isolating contact unit, and to said electronic interruption unit, and wherein a process for interrupting a current flow in the phase conductor is initiated when the current in the phase conductor exceeds a threshold value or a current/time threshold value; and
said electronic interruption unit being configured to be switched, via semiconductor-based switching elements, to a high-impedance state of the switching elements to prevent a flow of current or to a low-impedance state of the switching elements for the flow of current in the low-voltage circuit.
2 . The circuit breaker device according to claim 1 , wherein said mechanical isolating contact unit comprises:
a contact for enabling a switching between opening the contact in order to prevent a flow of current or closing the contact for a flow of current in the phase conductor path; and
a handle for manually opening and closing the contact.
3 . The circuit breaker device according to claim 2 , wherein said mechanical isolating contact unit is configured to enable said contact to be opened, but not closed, by the control unit.
4 . The circuit breaker device according to claim 2 , wherein said mechanical isolating contact unit is configured to enable a closing of said contact by way of a handle only when an enable signal is present.
5 . The circuit breaker device according to claim 1 , wherein said mechanical isolating contact unit is configured to make available an item of position information about a closed state or an open state of the contacts.
6 . The circuit breaker device according to claim 5 , wherein said control unit is connected to receive the item of position information about the closed state.
7 . The circuit breaker device according to claim 1 , further comprising a second voltage sensor unit for ascertaining a level of a voltage between said grid-side neutral conductor connection and said grid-side phase conductor connection.
8 . The circuit breaker device according to claim 1 , further comprising at least one of a switch or a fuse disposed in a connection between said grid-side neutral conductor connection and said power supply unit or between said grid-side phase conductor connection and said power supply unit.
9 . The circuit breaker device according to claim 1 , further comprising a display unit connected to said control unit.
10 . The circuit breaker device according to claim 1 , further comprising a communication unit connected to said control unit.
11 . The circuit breaker device according to claim 1 , further comprising a temperature sensor unit.
12 . The circuit breaker device according to claim 11 , wherein said temperature sensor unit is configured to ascertain a temperature of said electronic interruption unit.
13 . The circuit breaker device according to claim 1 , wherein said electronic interruption unit is configured to be switched, by way of semiconductor-based switching elements, to a high-impedance state of said switching elements in order to prevent a flow of current or to a low-impedance state of said switching elements for a flow of current in the low-voltage circuit.
14 . The circuit breaker device according to claim 1 , wherein the low-voltage circuit is a three-phase AC circuit and the circuit breaker device comprises further grid-side and load-side phase conductor connections, between each of which there is connected a series circuit formed of a further contact of said mechanical isolating contact unit and electronic interruption units, and wherein further current sensor units are provided to ascertain a level of the respective phase conductor.
15 . The circuit breaker device according to claim 1 , wherein:
when contacts of said mechanical isolating contact unit are closed and said interruption unit is at low impedance; and
when a current is ascertained which exceeds a first current value, said electronic interruption unit comes to have a high impedance and said mechanical isolating contact unit remains closed;
when a current is ascertained which exceeds a second current value, said electronic interruption unit comes to have a high impedance and said mechanical isolating contact unit is opened;
when a current is ascertained which exceeds a third current value, said electronic interruption unit comes to have a high impedance and said mechanical isolating contact unit is opened.
16 . The circuit breaker device according to claim 1 , wherein:
when the current exceeds a first current value for a first time limit, said electronic interruption unit comes to have a high impedance and said mechanical isolating contact unit remains closed;
when the current exceeds a second current value for a second time limit, said electronic interruption unit comes to have a high impedance and said mechanical isolating contact unit is opened.
17 . The circuit breaker device according to claim 1 , wherein said control unit has a microcontroller.