Siemens SIMATIC NET PROFIBUS manual Cabling within Closets, Cabling within Buildings

Installing LAN Cables

C.5.2 Cabling within Closets

When cabling within wiring closets, note the following points:

SThe minimum clearance between cables of different categories can be found in Table C-1. In general, the risk of interference due to crosstalk is less the greater the clearance between the cables.

SWhere cables of different categories cross, they should cross at right angles (keep sections where the cables run parallel as short as possible).

SIf there is not enough space to maintain a clearance≥ 10 cm, the cables should be arranged according to their categories in separate metal, conductive channels. These channels can then be arranged next to each other. The metal, conductive channels should be screwed to the struts of the rack or the closet walls making low-resistance and low-inductance contact.

SThe shields of all cables entering the wiring closet must be secured as close as possible to the point of entry and should make large-area contact with closet ground.

SParallel routing of incoming cables and internal closet wiring between the point of entry into the closet and the shield clamp should be avoided at all costs even with cables of the same category.

C.5.3 Cabling within Buildings

When laying cables outside cabinets but within buildings, note the following points:

SThe clearances listed in Table C-1 must be maintained between the various cable categories and when laying cables on common cable racks.

SIf the cables are laid in metal cable channels, the channels can be arranged directly beside each other.

If there is only one common metal channel available for all categories, either the clearances shown in Table C-1 must be maintained or if this is not possible for lack of space, the individual categories should be separated from each other by metallic partitions. The partitions must be connected to the channel making low-resistance and low-inductance contact.

SCable racks should cross each other at right angles.

SInclude metal, conducting cable channels/racks in the equipotential bonding of the building and between the individual parts of the system.

SNote the information on equipotential bonding in Section C.4.4 in this manual.

C-16	PROFIBUS Networks SIMATIC NET
	6GK1970-5CA20-0AA1 Release 2 05/2000