In case of high switching capacities, it is difficult to fully encapsulate compact low-voltage switchgear with deion chamber. Encapsulation is supposed to prevent the release of ionised gases. However, this measure negatively affects the arc running and current limitation in the majority of cases. The technical problems arising from the encapsulation of switchgear with deion chamber and running rails are described. A method to encapsulate such an arrangement as well as its efficiency is shown based on experiments with different loads. In particular, a new deion chamber is presented which allows high arc speeds and fast arc division despite of a fully encapsulated switchgear. At the same time, stable and defined arc running in the deion chamber is achieved and reignition is reliably prevented. The deion chamber allows a compact design of the arrangement, particularly due to the stable number of partial arcs and the high voltage of the partial arcs of 30-40 V. Arrangements with compact dimensions can also be used for high nominal voltages and high prospective short-circuit currents exceeding 50 kA. The benefits of this arrangement are described based on the operating behaviour of a lightning current arrester. These surge protective devices place particularly high requirements on the encapsulation due to the injected lightning currents. In addition, the basic requirements on modern lightning current arresters are briefly described. The load on the deion chamber in case of mains follow currents and lightning impulse loads is described and discussed.
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