A Study of Electrode Mass Change and Arc Energy of AgNi Contacts for Electromagnetic Contactor

摘要

The authors have been examining a method of evaluating the electrode mass change of AgNi contacts for an electromagnetic contactor with DC load current at a resistive circuit. We carried out experiments of 100,000 operations at a load current of 5A constant with a source voltage change from 100 to 160V. The experiments were carried out under the three operation modes that were classified by the arc discharge. The arc duration, contact resistance, arc energy, and electrode mass changes were measured. The electrode mass change per unit arc energy was calculated in cathode and anode of stationary contacts. As the results, when make and break arcs were generated, the mass of cathode electrode decreased and the anode electrode increased. On the other hand, when only a make arc was generated, the mass of cathode electrode increased and the anode electrode decreased. In addition, when only a make arc was generated, the electrode mass change per unit energy were about ten times larger than make and break arcs were generated.