Specification Document Compact Data Trunking 140 X 50

Specification document Compact Data trunking 140 x 50

1 COMPONENT SPECIFICATIONS

1.1 Pathway systems

1.1.1 Trunking systems

1.1.1.1 General

All trunking shall comply with BS EN 50085-2-1: Cable trunking systems and cable ducting systems for electrical installations” Part 2-1: Cable trunking systems and cable ducting systems intended for mounting on walls and ceilings. Documentary evidence of compliance shall be made available on demand.

All trunking used to contain telecommunications (voice and/or data) cabling shall meet the requirements of clause 1.1.1.2 and 1.1.1.3.

Where the trunking contains, or is intended to contain, both telecommunications cabling and mains power cabling then the trunking shall additionally meet the requirements of clause 1.1.1.4.

Clause 1.1.1.4 contains requirements in accordance with the combined requirements of BS 6701 (2004): Telecommunications equipment and telecommunications cabling - Specification for installation, operation and maintenance which requires conformance with BS EN 50174-2: Information technology. Cabling installation - Installation planning and practices inside buildings. EN 50174-2, first published in 2001, has been revised and ratified in as a European norm in 2008. This standard contains new requirements for segregation based upon the performance of the telecommunications cables and the type and quantity of mains power circuits. Any trunking systems that do not meet the specific requirements of 1.1.1.4 shall provide evidence that they conform to these two standards.

1.1.1.2 Appearance

The trunking shall comprise an integrated system from a single manufacturer and only components from that system shall be used to implement the trunking system.

The trunking system shall be of a design that can be used as either “skirting” (where appropriate) or “dado” containment.

1.1.1.3 Dimensions and space allocation

1.1.1.3.1 Category 5/5e and Category 6 cabling

For trunking systems intended to contain cables of up to Category 6 (in accordance with BS EN 50173-1:2007 and ANSI /TIA/EIA-568B.2), the space within the trunking system that is allocated to telecommunications cables shall be capable of containing at least 9 No. cables of 7.5 mm diameter without crushing or deformation of the cable sheath.

NOTE: this requirement applies at the points of greatest restriction e.g. at corners or around fittings within the containment.

1.1.1.3.2 Augmented Category 6 and Category 7 cabling

Recent developments in the area of telecommunication cable design has introduced products with increased diameters. Unscreened “Augmented Category 6” cables (in accordance with ANSI /TIA/EIA-568B.2-10) are considered the largest products. Screened “Augmented Category 6” and Category 7 (in accordance with BS EN 50173-1:2007) are typically slightly smaller.

The space within the trunking system that is allocated to telecommunications cables shall be capable of containing at least 8 No. cables of 8.0 mm diameter without crushing or deformation of the cable sheath.

NOTE: this requirement applies at the points of greatest restriction e.g. at corners or around fittings within the containment.

1.1.1.3.3 Terminations

Where the trunking system houses, or is intended to house, termination points/outlets then it shall:

provide adequate depth for the termination of the cabling to be undertaken in accordance with the instructions supplied by the manufacturer of the connecting hardware, without crushing, kinking or deforming the cable sheath and maintaining the minimum cable bend radius (post-installation) specified by the manufacturer of the cable;
where the proposed cable bend radius is not known then a figure of 35 mm shall be used;
provide internal structures to prevent telecommunications cables within the trunking fouling the rear of the termination points
Boxes for termination points/outlets shall provide means for adjusting its total internal depth between 38 to 42mm to safely cater for most common types of data module types and electrical accessories available on the market
Termination/outlet boxes shall provide a concave back wall to avoid internal right angles which can induce excessive cable dragging and bending.
Termination points / outlets shall incorporate top and bottom knock-out holes with angled edges parallel to the direction of the cable. This will maximize the flat contact area between box and cable reducing the risk of damaging external sheathing of the cable and compromising performance.

The trunking system shall enable changes of direction using fittings to provide:

variable-angle internal corners with built-in living hinge for adjustment;
variable-angle external corners with built-in living hinge for adjustment;
90o flat angles;
T-pieces.

The fittings used shall:

maintain, as continuous, the protection to the cabling, provided by the trunking system;
maintain, but not enlarge, the minimum requirements for cable capacity of the trunking system (as detailed in 1.1.1.3.1 and 1.1.1.3.2);
ensure that the maximum number of cables (specified above) are able to follow the change of direction without crushing, kinking or deforming the sheath and maintaining the minimum cable bend radius (post-installation) specified by the manufacturer of the cable;
where the proposed cable bend radius is not known then a figure of 35 mm shall be used;
meet the requirements of 1.1.1.4 where appropriate.

1.1.1.4 Mains power segregation

The trunking system shall feature separate and independent access to sections containing telecommunications cabling and mains power cabling.

For the purpose of protection (i.e. human safety and equipment protection) and in accordance with BS 6701, an internal barrier within the trunking system shall separate the mains power cabling and the telecommunications cabling. The internal barrier may be either non-conductive or conductive – if conductive; the barrier shall provide protective earth continuity in accordance with local electrical safety regulations.

NOTE: metallic films and foils are not considered adequate to provide protective earth continuity.

EN 50174-2:2008 specifies minimum separations between telecommunications and main power cabling for the purpose of electromagnetic immunity (i.e. electrical interference from the mains cabling to the telecommunications cabling). The requirements are scaled, based upon the current carried by the mains power cables and the electromagnetic immunity performance of the telecommunications cabling.

Table 1: Separation distance for electromagnetic immunity

Telecommunications cable performance / Unrestricted / Category 5 (min)
Minimum separation distance (mm)
Total current capacity @ 230 V
60 A / 60 / 20
120 A / 120 / 40

Within trunking constructed from non-conductive materials it is necessary to provide a minimum separation as detailed in Table 1. In Table 1, maximum design current capacity of the mains power compartment shall be defined by the supplier of the trunking assuming that each mains power circuit comprises separate conductors (i.e. not twin-and-earth).

For example, if the trunking supplier provides installation instructions that limit the mains power current to 120 A, then the trunking supplier shall guarantee, either by the use of internal fittings or by the application of installation rules, a minimum separation of:

40 mm, if the trunking is designed specifically to support telecommunications cabling of Category 5 minimum;
120 mm, if there is no restriction on the type of telecommunications cabling that may be installed.

It should be noted that the presence of conductive barriers, within non-conductive trunking, that separate the mains power cabling from the telecommunications cabling do not allow any reduction of the separation requirements of Table 1.

The minimum separation distance applies at all points in the trunking including locations where cables are terminated.

2 INSTALLATION PRACTICE

2.1 Pathway systems

2.1.1 Trunking systems

2.1.1.1 General

The trunking system shall be installed using only components specified by, and in accordance with the installation method statements provided by, the supplier of the trunking system.

2.1.1.2 Installation of telecommunications cables within trunking systems

Telecommunications cables shall only be installed within the section of the trunking system specified by the supplier of the trunking system to house such cables.

The quantity of cables installed shall not exceed the maximum number specified by the supplier of the trunking system as appropriate for the diameter of cables used.

Fittings that are required to maintain segregation between telecommunications and mains power cabling shall be as supplied, and used in accordance with the installation method statements provided, by the supplier of the trunking system.

2.1.1.3 Installation of mains power cables within trunking systems

Installation method statements shall define the maximum quantity of electrical circuits (as defined in Table 1) that may be installed in order that the separation provided by the design of the trunking provides the required electromagnetic immunity for the telecommunications cabling (see Table 1).

Mains power cables shall only be installed within the section of the trunking system specified by the supplier of the trunking system to house such cables. Fittings that are required to maintain segregation between telecommunications and mains power cabling shall be as supplied, and used in accordance with the installation method statements provided, by the supplier of the trunking system.

2.1.1.4 Installation of conductive barriers within trunking systems

Conductive barriers shall only be installed within the section of the trunking system specified by the supplier of the trunking system to house such barriers and in accordance with the design rules supplied provided by the supplier of the trunking system.

Where the barriers are installed for the purpose of protection then the design rules supplied by the supplier shall meet or exceed the requirements of BS 6701 (see clause 1.1.1.1).

2.1.1.5 Earthing of conductive barriers

Where conductive barriers are installed within trunking systems for the purpose of protection then the barriers shall be earthed in accordance with local electrical safety regulations.

V 07-2008