| 摘要 |
<p>The electrical protective device contains a fusible conductor wound on a former and arranged around a device indicating operation of the protective device, which has a moving bolt which is used for tensioning a spring device with a predetermined tensioning force via a tensioning wire, which is connected to the bolt and which breaks under the tensioning force on operation of the protective device. It is intended that this protective device should detect an overload of the fusible conductor below a disconnection current leading to its melting. To this end, it is provided according to the invention that the spring device (10) contains a spring element (12), which consists of an alloy with a temperature-dependent shape-changing characteristic such that, if a predetermined critical temperature is exceeded, the spring element (12) expands to such an extent that the tensioning wire (16) breaks on the basis of a corresponding heating power of the fusible conductor (4) when it is overloaded. As an alternative, according to the invention, a spring element of such an alloy can also be arranged in front of the bolt such that in the case of heating power from the fusible conductor in the case of an overload, the spring element deforms with an effective component in the direction of operation of the bolt. <IMAGE></p> |
