Overcurrent protection relay with excitation and load windings - wound on common core but in opposite senses so that overcurrent induces magnetic field overcoming excitation field

摘要

The relay has an armature (11), an excitation winding (12) and current winding (13). The armature operates contacts (14,15) one of which (14) is a latching contact and the other (15) is in the power circuit coupled to the load. Switch-on is produced by operation of a pushbutton (16). If a overload current is generated the excitation field is interrupted and the load is disconnected. ADVANTAGE - Has excitation and load working on some former for simple construction.