A new computation model of contact breaking arc duration

A new analytical computation model of contact breaking arc duration is proposed in this paper based on Mayr equations and load circuit equations. The model is obtained by the assumption that electric arc current is varying according to inverse exponential law. The arcing process is divided into three stages to deal with. The influences of contact breaking velocity, load current and inductance on the arcing time are also considered in this model. It ensures that the model is appropriate to explain the reported experimental results. The validity of the model is proven by arcing experiments using a 10A-DC relay. With the help of this model, discrete experimental results can be normalized, the parameters like contact breaking velocity and opening gap of contacts can be designed properly, and the limit values of inductance and current can be correctly calculated.