Two Different Experimental Approaches to Investigate the Influence of Gassing Polymer Walls on Switching Arcs in Miniature Circuit Breakers

Experiments with high current arcs confined in gassing polymer walls for two different experimental setups and characteristics of the current source were carried out. The first setup consists of a rotationally symmetric electrode configuration with the arc burning inside a small polymer tube. For the second setup conventional 16 A miniature circuit breakers were slightly modified by changing the geometry of the polymer gassing inserts and by drilling a small channel for the measurement of pressure inside the arc chamber. The signals of arc current and voltage and pressure inside the arc chamber using 9 different polymers and a not gassing ceramic were measured and compared. The paper presents the results of the different experimental approaches and evaluates the differences due to the corresponding setup. The influence of the polymers on the interrupting performance of the breakers is described.