This is the third in a series of posts where we offer guidelines on how to produce a specification for an IT cabling system.
Today we look at what you should consider when installing containment and cable, and we list the components which make up a well-documented cabling system.
CABLE PATHWAYS AND CONTAINMENT
Cable pathways can be located above ceilings, under floors, in risers between floors, underground or overhead between buildings. In most instances, the cabling will require dedicated containment such as trunking, conduit, cable tray, matting, cable basket or ducts.
The following should be considered:
- Designing pathways that keep cable lengths within limits
- Specifying the most suitable containment for the pathway
- Consider who has responsibility for the pathways and designing the containment system, e.g. architect, mechanical and electrical contractor or the cabling installer
- Capacity, allowing for future growth and to keep fill ratios within the requirements of the BS and EN standards
- Segregation from other services, particularly electricity supply cabling in accordance with your country’s standards, in the case of the UK it is BS 6701 and BS EN 50174-2 series
- Suitability for standards conformity e.g. to allow correct bend radii for cables
- You have permission from the landowner for the installation of ducts
- Protection of the cable from water, heat, sunlight, physical damage and rodents.
Suitably qualified installers, complying with relevant standards should be selected to undertake the cabling work. Qualifications would include evidence of the cable manufacturer’s training or training undertaken at a specialised training establishment and supported by a recognized certification.
The installation should adhere to standards, including, where applicable:
- BS 6701
- BS EN 7671 (IEE) Wiring Regulations – 17th Edition
- BS EN 50174 series of standards
- BS EN 50310
- BS EN 50346
A good installer will not:
- Exceed the minimum bend radii for cables
- Exceed the maximum pulling force for cables
- Crush cable (e.g. by over tightening cable ties)
- Strip too much cable sheath at termination points
- Install cables where they could be damaged
- Untwist too much of each cable pair
- Use incorrect tools or fixing techniques.
A good installer will:
- Work safely
- Adhere to the necessary standards
- Always follow the manufacturer’s guidelines.
LABELLING, RECORDS AND DOCUMENTATION
If your cabling system is well documented, any implementation, moves, additions or changes will be made simpler and problems more quickly diagnosed. You should develop a full administration scheme, complying with BS 6701 or your own country’s standards.
The level of detail will depend on the size and nature of your network and will include the following:
Labelling and records:
- Work Orders (documenting all moves, additions and changes).
Documentation should contain some or all of the following:
- Topology diagram (schematic layout)
- Floor plans routes
- Equipment room layout
- Outlet locations
- Patching closet location
- Equipment termination location
- Telecommunications or equipment room layout
- Cabinet layout
- Patching / cross connect records
- Test schedules / results
- Identification of test equipment used
- Certificate of conformity.
Depending on your experience and the complexity of the installation, expert assistance may be needed to complete the specification.
Watch out for the final post on how to specify an IT cabling system:-
- Testing of Copper and Fibre Links [Part 4]