Analysis of Electrical Contact Performance for Alternating Current Contactor

AC contactor is an important component in the control system, and its reliable work is very important too. Electrical contact is a contactor´s connecting parts, and it undertakes making and breaking the current. So, it´s performance influence the reliable operation of the contactors directly. CJ20-40 AC contactor emerged sticking phenomenon in the course of practice using. So, the electrical contact performance of this type AC contact is analyzed detailed. In order to analyze its electrical contact properties better, multiple contactors were tested by using electrical contact material parameter tester. The surfaces of these contactors were analyzed by using SEM and EDS after the test. These microstructures and EDS of the contact surface is the same with those contact surfaces in practice using. Also, the main melted metal is silver. So, through the analysis, we found that the failure reason is the welding strength increased in practice using.