Various characteristics of electromagnetic contactor when arc discharge are generated only make arc

Experiments are carried out to clarify the influence on the current and voltage for various characteristics. A small electromagnetic contactor that has two contacts is used. The arc discharge with only a make arc is generated and various characteristics are measured. Source voltage is set to 100V or 3V DC, closed contacts currents are changed from 10A 20A and 30A. From the waveforms, the arc duration time and the bounce time are read out. Arc energy is calculated from the arc voltage and arc current. The contact resistance is calculated from the voltage drops. In DC100V, the arc duration time and the bounce time were not influenced by a closed contact current. The arc energy was increased by a closed contact current. The contact resistance was slightly decreased with current increases. The mass change of electrodes, the anode was decreased and the cathode was increased. Further the electrode mass change per unit arc energy vs. closed current was relatively constant. But, in DC3V make arc duration is very short and electrode mass change is very small.