DIY Knowledge

Electric fuse protection

Absicherung, elektrische

Protección eléctrica

Sécurité, électrique

The weakest point in an electric circuit is the fuse. It is meant to burn out before any elements in the chain are damaged. The fuse is meant to protect the power line and has to match its diameter (or cross-section in mm2). The installed conductor diameter and the safety lead fuse or overload cutout belong together. They are defined in the VDE regulations as VDE standard 100. So if a stronger series-connected fuse has to be chosen to cope with the higher intensity of current which results from the increased starting current of an appliance, the diameter of the supply conductor has to be enlarged too.

The fuse does not protect the connected power tool against overloading. For this purpose you need a motor safety switch or an electronic cutout device.