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Guidelines for Cabling in the Cabinet
Guidelines for Cabling in the Cabinet
Guidelines for Cabling The following guidelines apply when cabling the cabinet: As with external cabling, the cabling guidelines also apply to cables inside the cabinet, Cabling, page135. Conductive coupling between the interference current dissipation of filters and cable shields with the reference conductor system must be avoided. For analog process signals, shielded twisted outgoing and return conductors should be selected.
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Guidelines for cable ducts in the cabinet
The following guidelines must be observed when running and combining cables in the cable ducts: 115/230 VAC mains and signal lines and 24/60 VDC signal lines must be laid in different cable ducts. The distance between the ducts must be at least 100 mm. Unavoidable crossing must be at right angles. Digital signal lines (24/50 VDC) may be unshielded in a common cable channel. The following cables can be combined in a cable duct: Shielded bus cable Shielded analog process signal cable Unshielded 24/60 VDC signal lines
Guidelines for installing cables The following guidelines should be observed when installing cables in cabinets: The selection of the housing lead through must be made very carefully as this is the connection with the earthing system. Interfering cables must be filtered before entering the cabinet.
Guidelines for filters The following guidelines should be observed when using filters: The filter must have a good conductive ground connection. The filters input line may not be laid together with the filters output line or with other signal and supply lines. When mounting the filter near a cable entrance (distance from floor or wall < 100 mm), the line to the filter is only twisted. When mounting a filter further than 100 mm away from the cable entrance, the line through the cabinet must be twisted and shielded.