Lightning and overvoltage protection device for shielded cable as building protection device

摘要

2.1 The invention is based on the object of creating a lightning and overvoltage protection device for screened cables by means of which overvoltage levels on the cable screening inside unscreened rooms, resulting from lightning strikes or EMP events, are reduced to tolerable limits. 2.2 This object is achieved in that an earthing system is connected to the cable screen (2) in each case on the outer and inner side of the room boundary (10) in the region of the insertion point of the cable (1), in that the earthing systems consist of a circumferentially contacting cable duct (5, 13), a large-area dissipation plate (4, 12) and an earthing conductor (7, 14), in that the cable (1) has a mutual inductance between the outer (4) and inner (12) dissipation plate which consists of the line inductance (11) of the cable screen (2) and of at least one ferromagnetic surround (21), and in that the surround (21) is electrically insulated from the outer dissipation plate (4) and is electrically short-circuited to the inner dissipation plate (12). 2.3 The invention is used in lightning and overvoltage devices for screened cables which are introduced into unscreened rooms and whose cable screening is earthed to a connected earthing conductor at the introduction point. IMAGE