Multi-stage protection device for the overcurrent- and overvoltage-protected transfer of electrical energy

A protective device for overcurrent and overvoltage protected transmission of electrical energy from a voltage terminal to an electrical load wherein the voltage terminal has two poles, comprising:

• a first fuse circuit adapted to interrupt a flow of a line current from the voltage terminal to the electrical load when an intensity of the line current intensity reaches a first current intensity limit value;
• an overvoltage protection circuit connected downstream of the first fuse circuit and upstream of the electrical load, wherein the overvoltage protection circuit is adapted to connect the poles of the voltage terminal in an electrically conductive manner, when a first voltage limit value of a voltage is reached on the first fuse circuit, to force the line current to reach the first current intensity limit value;
• and
• a second fuse circuit which is connected downstream of the overvoltage protection circuit and upstream of the electrical load wherein the second fuse circuit is also adapted to activate the overvoltage protection circuit when a second voltage limit value of a voltage on the second fuse circuit is reached in order to connect the poles of the voltage terminal in an electrically conductive manner, and wherein the second voltage limit value is based at least in part on a nominal voltage of the electrical load.