Comparison of experimental results about the influence of gassing walls of different plastic compounds on arcs confined both in tubes and in MCBs

Experiments with arcs confined in tubes and Miniature Circuit Breakers - MCBs with gassing walls of different engineering plastic compounds were carried out. In the first part of the investigation the arc chamber consisted of small tubes of the different materials. The arc-current source was a damped capacity bank with high charging voltages. For the second part of the investigation customary 32 A MCBs were used with gassing inserts of the different materials, which replaced the standard gassing polymer. The arc currents were provided from a power transformer connected to the 20 kV 50 Hz network. The influence of gassing effects of 8 different plastic compounds and Al₂O₃ ceramic (as reference) on arcs with amplitudes of 1 kA and 3 kA (tubes) and of 1 kA (MCBs) was investigated. Arc signals of current and voltage and of pressure (for the setup with polymer tubes) were recorded. The paper presents the comparison of the measured values for the two different experimental setups and arc-currents. The correlation of the experimental results regarding the polymer influence on the arc is discussed.