S 5.4 Documentation and labelling of cables

Initiation responsibility: Head of IT, Building Services Manager

Implementation responsibility: Building Services, Administrator

Good documentation and clear identification of all corresponding components are necessary for maintenance, troubleshooting, repair work, and successful testing of the wiring. The quality of this review documentation depends on the completeness, up-to-dateness, and readability of the documents. In any case, a person responsible for the documentation of the cabling must be appointed.

Since it is impossible to include all information in a single plan as the size of the network increases, it is advisable to divide such information. Actual location information is always to be drawn in scale plans. Other information can be listed in tables or schematic plans. An important point in this regard is to ensure all information is clearly organised. The documentation therefore should consist of descriptive documents, lists, and plans.

The descriptive documents, such as a documentation guideline, contain information on the documentation procedures and labelling/identification rules. These documents should describe in general, for example, which lists and plans need to be drawn up and how these documents are to be maintained in an audit-proof manner.

The lists and equipment location plans must contain all items affecting the network. The lists should contain the following information, amongst other things:

• supplier and component information,
• exact cable types (including the fibre quality for fibre optic cables),
• usage-oriented labelling of cables,
• locations of the central distribution points and distributors, including precise designations and access rules with contact persons for the buildings and rooms,
• equipment location plans for all terminal blocks and distributors,
• usage of all lines and specification of the connected network subscribers,
• technical data of connection points,
• hazardous spots,
• existing protection measures and protection measures to be reviewed.

The equipment location plans typically contain the following information:

• an overview of the location and scaled location plans, including the exact locations of trays and channels and of the primary wiring routes,
• building sections as a schematic plan and scaled floor plans with the exact locations of and routes in distribution rooms, cable channels and trays, and the IT connections per room in, for example, cable ducts and/or floor outlets,
• technology room plans with the room layout, raised floor pattern and cabinet positions, power distribution (KuV), and potential equalisation bar as well as air conditioners present,
• cabinet projection diagrams showing the correct positions of the passive and active components installed, including the power strips,
• physical and logical network connection plans.

It must be possible to quickly and easily obtain an exact picture of the wiring based on this documentation.

To guarantee the documentation is up-to-date, it must be ensured that the person maintaining the documentation is properly informed of all work done on the network in a timely and complete manner. For example, it is possible to require the issuance of material, awarding of contracts, or releases for secured areas to be signed by the person fulfilling this function.

Since the documentation contains sensitive information, it must be stored securely, and access to it must be controlled. Furthermore, the cables themselves are to be labelled so that they can be associated with the information in the equipment location plans. The cables must be labelled on both ends. If necessary, labels can be applied repeatedly to the cable so it can be clearly identified when tracing its route. Labelling sheets or bands are to be used, and they must be printed either manually or by machine so they are always legible. It is often not enough to label the cables using a transparency marker.

The cables and wires should always be labelled or marked in such a manner that the labels or markings only contain references to the documentation. Labels or markings which make it possible to directly derive the importance of the cable or line must be avoided at all costs insofar as such labels or markings are not required by other rules or regulations.

It is advisable to start the documentation process while planning the wiring measures using such a tool and then carry over the documentation from the planning state to the production state after implementation. In this manner, it is easier to inform the users of the documentation of pending changes and to keep the documentation up to date.

Review questions:

• Is there a person responsible for documenting the wiring (in terms of completeness, up-to-dateness, and readability)?
• Are there list and equipment location plans containing all information related to the network?
• Is it ensured that the employee responsible for documentation is informed promptly and completely about all work on the wiring?
• Is the documentation of the wiring stored securely and is the access controlled accordingly?
• Are the cables labelled in such a way that matching the information from the equipment location plans is possible?