Abstract: Abstract:Due to loop resonance, a 380V AC contactor is unable to reset normally. The abnormal phenomenon was analyzed by numerical calculation. The analysis result shows that the main reason of the problem is the influence of the distributed capacity of the cable. A solution was proposed, which is to connect an additional contactor parallel with the original contactor. The matters needing attention in field application of 380V AC control circuit were given.

Key words: Keywords:AC contactor, AC impedance, resonance