Semi voltage dependent circuit breaker with earth fault and overcurrent protection

1. An alternating current circuit breaker, comprising:

a live line between a live supply connecting terminal and a live load connecting terminal;

a neutral line between a neutral supply connecting terminal and a neutral load connecting terminal for connecting an alternating current load to a mains supply;

a first galvanic separation switch and a bypass switch in the live line;

a second galvanic separation switch in the neutral line;

a semiconductor switch element connected parallel to the bypass switch;

a processing unit configured to control the first and second galvanic separation switches, the bypass switch, and the semiconductor switch element; and

a power supply unit connected to the live supply connecting terminal and to the neutral supply connecting terminal, and connected to at least the processing unit of the alternating current circuit breaker for providing electrical operating power thereto,

wherein the power supply unit has a minimum operating voltage of a predetermined value, and

wherein the power supply unit includes a power reserve unit configured to supply operating power to the power supply unit for at least a first time period after a voltage of the mains supply drops below the minimum operating voltage.

2. The alternating current circuit breaker of claim 1 , wherein the power reserve unit includes a capacitor including a minimum storage capacity.

3. The alternating current circuit breaker of claim 1 , wherein the processing unit is configured to determine an under voltage situation if the supply voltage of the mains supply is lower than the minimum operating voltage, and to switch off the alternating current circuit breaker in case of an under voltage situation.

4. The alternating current circuit breaker of claim 1 , wherein the processing unit further includes a non-volatile memory to store status data of the alternating current circuit breaker directly before a switch off actuation.

5. The alternating current circuit breaker of claim 4 , wherein the status data includes switch positions of the bypass switch and the galvanic separation switches, and a status of the semiconductor switch element.

6. The alternating current circuit breaker of claim 4 , wherein the status data further includes a load current value as measured directly prior to a switch off actuation of the alternating current circuit breaker.

7. The alternating current circuit breaker of claim 4 , wherein the processing unit further includes a real time clock to determine a time period since a switch off actuation of the alternating current circuit breaker.

8. The alternating current circuit breaker of claim 1 , wherein the processing unit is further configured to wait a second predetermined time period after the mains supply is restored before determining whether or not to switch the alternating current circuit breaker on depending on a status stored in a non-volatile memory.

9. The alternating current circuit breaker of claim 8 , wherein the second predetermined time period is equal to a time needed to recharge the power reserve unit.

10. The alternating current circuit breaker of claim 8 , wherein the first and the second predetermined time periods are programmable.

11. The alternating current circuit breaker of claim 1 , wherein the bypass switch and galvanic separation switches are actuated using stored electrical energy sufficient for at least two actuations of the associated bypass switch and galvanic separation switches.

12. The alternating current circuit breaker of claim 1 , wherein the processing unit is connected to an on/off toggle switch, and

wherein the processing unit is further configured to block actuation of the bypass switch relay if the on/off toggle switch is in an off position.

13. The alternating current circuit breaker of claim 5 , wherein the status data further includes a load current value as measured directly prior to a switch off actuation of the alternating current circuit breaker.

14. The alternating current circuit breaker of claim 5 , wherein the processing unit further includes a real time clock to determine a time period since a switch off actuation of the alternating current circuit breaker.

15. The alternating current circuit breaker of claim 6 , wherein the processing unit further includes a real time clock to determine a time period since the switch off actuation of the alternating current circuit breaker.

16. The alternating current circuit breaker of claim 13 , wherein the processing unit further includes a real time clock to determine a time period since the switch off actuation of the alternating current circuit breaker.