Circuit breaking switch i.e. relay, operating method for electrical motor car, involves electrically insulating terminal elements and contact bridge from each other if voltage dropping over contact exceeds fixed value for time duration

摘要

The method involves continuously or periodically measuring a voltage dropping over a switching contact of a circuit breaking switch by an ammeter and a voltmeter. Metallic terminal elements and a contact bridge of the switching contact are electrically insulated from each other if the voltage dropping over the switching contact exceeds a fixed value for a preset time duration, which is less than or equal to 10 ms. The contact bridge is connected with an armature, which is moved to and fro between two positions by a magnetic drive.