Current protection switch with thermal and differential elements - provides over-current and fault current protection having release coupling between separate elements

摘要

The switch has a modular insulating housing with one part containing a thermal switch mechanism and the other part containing a differential switch mechanism. The two mechanisms are coupled together via a release armature having an adjustment screw at one end cooperating with a release lever. The release lever pivots about a shaft formed integrally with the switch housing and its other end acts against a release button of a polarised relay. The thermal mechanism provides over-current protection, while the differential mechanism provides fault current protection, with the simplified coupling between them reducing the likelihood of switch failure.