Patent ID: 7158369

Claim:
Single phase or polyphase switchgear comprising one or more switches which are mounted with the aid of solid insulation such that they are insulated, as well as associated live components such as rail systems, connectors and the like, wherein both the switches and the associated live components are housed in a housing enveloping said switches and live components, characterised in that the enveloping housing is filled with air having a low moisture content and the interior space thereof is sealed with respect to the exterior space around the enveloping housing in such a way that the air present in the housing is not contaminated and will not reach the dew point, characterised in that a moisture-absorbent agent is arranged in the enveloping housing, the quantity of said moistureabsorbent agent being such that the moisture that penetrates as a result of leakage of the enveloping housing is absorbed during the life of the switchgear, and characterised in that the amount of absorbent is determined by the equation D=(L×V×Y+I×J)×100/O+S×F×100/O where D is the amount of desiccant required in grams assuming a specific amount of leakage L per day in m 3 , V is the moisture content in grams per m 3 of the ambient air that may penetrate at a specific temperature, Y is the expected life of the installation in days, I the capacity of the interior space in the housing in m 3 , J the moisture content of the air present in the interior space during manufacture in grams per m 3 and at a specific temperature, O is the absorbency of the moisture-absorbent agent, S is the amount by weight of the moisture-containing material in the interior space in grams and F is the moisture content of the moisture-containing material in percent.