Switching device with overvoltage protection and isolating properties and method for protecting a switching device against overvoltages

摘要

The invention relates to a switching device with overvoltage protection and isolating properties a) with a mechanical first switch (K1) via which a load (Z) can be connected to an electrical voltage source (DC), the contact elements (KS, KL) when the first switch is opened (K1) temporally go through a contact phase (BP) and then a separation phase (TP), b) with an energy storage circuit (B) which has an electrical energy storage element (S), which when the first switch (K1) is closed by the voltage source (DC) is chargeable, and at the beginning of the separation phase (TP) takes over the direct current supply of the load (Z) at least partially and thereby at least reduces the energy flow over the contact elements (KS, KL) when an arc occurs between the contact elements (KS, KL). In order to protect the energy storage circuit (B) against overvoltages during operation, it is proposed that c) the energy storage circuit (S) correlates with the opening of the first switch (K1) from the voltage source (DC) behind the load-side contact element (KL ) can be switched in parallel to the voltage source (DC), that d) the connection is limited in time and that e) the time limit includes at least the beginning of the separation phase (TP). The invention also relates to a corresponding method. Overvoltage protection.