How to Specify a Category 5-Class D Cabling System
There are three principal standards-writing groups in the world concerned with
structured cabling. They are:
ISO - The International Standards Organisation, which writes for a global
audience. The appropriate standard for cable system design here is ISO 11801.
CENELEC - The electrical standards body for the countries of the European
Union. CENELEC standards start with EN for European Norm. The appropriate
standard here is EN 50173. EN standards are normally adopted whole by British
Standards and would be published, in the UK for example, as BS EN 50173.
ANSI/TIA/EIA - ANSI is the standards approval body for the USA (American
National Standards Institute). They authorise the TIA and EIA to write to cabling
standards for America. The standard is ANSI/TIA/EIA-568-B.
In this document we will take the CENELEC standards as the lead and put other
relevant standards in parentheses next to them. We can assume that the three
document bodies are nearly identical in requirements unless this is particularly
highlighted in the text.
Relevant Articles:
Minimising Fire Risk in Computer Room Cable Installations
Cable Management
Specification Guide for Cable Marking and Administration
1
System Specification
The cabling system must be designed according to:
EN 50173-1:2002 Information Technology - Generic Cabling Systems -- Part 1:
General Requirements and Office Areas.
(ISO 11801:2002)
(TIA/EIA 568B)
All components must meet the Category 5 specification.
The cabling system must meet the Permanent Link and Channel performances
defined in these standards as Class D as a minimum.
The overall design must take into account any relevant portions of BS 8300
(access for the disabled) e.g. when selecting mounting heights for wall sockets.
2
Components Specification
2.1
Cable
2.1.1
2.1.2
The cable must be four-pair Category 5 with a low-flammability sheath.
The cable must be of the following construction (customer select):
UTP
or
F/UTP
2.1.3
2.1.4
2.1.4
Unscreened Twisted Pair
Foil screen around the cable pairs (plus a drain wire)
The cables must be metre marked.
The cable must be 100% tested per box.
The flammability performance must meet IEC 60332-1 as a minimum. The cable
construction must be (customer select):
PVC
or
LSZH
IEC 60332-1
IEC 60332-1
IEC 61034
IEC 60754
2.2
Connecting Hardware
2.2.1
Patch Panels
2.2.1.1
Must be 19” rack mounting, in exact multiples of 1U (44
mm) in height.
2.2.1.2
Cable termination must be Insulation Displacement
Connectors (IDC).
Front connectors to be RJ45 style IEC 60603.
Electrical performance to be Category 5.
2.2.1.3
2.2.1.4
The construction must be (customer select):
UTP
or
FTP
2.2.2
Connectors
2.2.2.1
2.2.2.2
2.2.2.3
Unscreened
Screened
Cable termination must be IDC.
Connectors to be RJ45 style IEC 60603.
Electrical performance to be Category 5.
The construction must be (customer select):
UTP
or
FTP
2.2.3
Unscreened
Screened
Patch Leads
2.2.3.1
Must be 24 AWG (UTP) or 27 AWG (STP) stranded, with
low flammability sheath to IEC 60332-1.
2.2.3.2
Connectors must be RJ45 style IEC 60603.
2.2.3.3
Electrical performance to be Category 5.
The construction must be (customer select):
UTP
or
STP
Unscreened
Select colour
Select length
Screened
Select colour
Select length
3
Installation Specification
3.1
3.2
The cabling system must be procured from one manufacturer.
The cabling system must be installed according to the manufacturer’s
instructions.
Planning, quality control, documentation and earthing/bonding must be
according to EN 50174 parts 1 and 2. External cables must be installed
according to EN50174 part 3.
Earthing and bonding must be according to the manufacturer’s
instructions and EN 50174-2, EN 50310 and BS 7671.
3.3
3.4
3.5
3.6
3.7
3.7
3.8
3.9
3.10
100% of the installed cables must be tested.
100% of the test data must be reviewed by the manufacturer and
approved by the manufacturer before any warranty certificate is released.
The Permanent Link must be tested to EN 50346 (IEC 61935) with a
Level III cable tester set to Class D Permanent Link referencing the
Permanent Link performance standards detailed in EN 50173:2002 Class
D. A Cat 5 generic interface must be used on the tester.
Cabling must be tested in both directions and the results stored in an
electronic database compatible with the tester manufacturer's cable
management programme.
The cabling must be covered by a manufacturer’s 25 year product and
application warranty and installed by an installer accredited and trained by
the manufacturer. Proof of training, which must be less than two years
old, must accompany the tender.
A labelling and administration system must be designed into the cable
system in line with EN 50174 or ISO 14763-2 or TIA/EIA-606.
Separation of power and data cables must be according to EN 50174 part
2 and BS 6701 except where local or national electrical safety regulations
require a greater separation.
4
LAN Applications
4.1
Any communications protocol designed for use on a 100-ohm (nominal)
characteristic impedance Class D cabling system must operate
satisfactorily on the installed cabling system. ‘Satisfactory’ shall mean
better than one in ten-to-the-power-of-ten bit error rate whilst in the
presence of up to 3 V/m external interference over 100 MHz for at least
thirty minutes.
LAN operation shall include, but not be limited to, Ethernet 100BASE-TX,
ATM at 155 Mb/s and Gigabit Ethernet to IEEE 802.3ab.
Delay skew of the Permanent Link shall be better than 20 nanoseconds
(typical) to ensure satisfactory video operation.
4.2
4.3
5
EMC Performance
The structured cabling system shall comply with cable balance and EMC
requirements of EN 61000 and ISO 11801:2002 and will not degrade the EMC
performance of any electrical device connected to it. This facility shall be
guaranteed by the manufacturer.
6
Reference to Standards
BS 6701
BS 7671
BS 8300
EN 50173
EN 50174
EN 50310
EN 50346
EN 61000
IEEE 802.3ab
IEEE 802.3an
ISO/IEC 11801
ISO 14763
IEC 60332-1
IEC 60603-7-4
IEC 61935
IEC 60754-1
IEC 60754-2
IEC 61034
ISO 11801:2002
TIA/EIA 568-B
TIA-606
Telecommunications Equipment and Telecommunications
Cabling. Specification for Installation, Operation and
Maintenance (2004).
Requirements for Electrical Installations (IEE 16th Ed)
Design of Buildings and their Approaches to Meet the Needs
of the Disabled.
Information Technology, Generic Cabling Systems (2002).
Information Technology, Cabling Installation. Parts 1, 2
(2000) and Part 3 (2003).
Application of Equipotential Bonding and Earthing in
Buildings with Information Technology Equipment.
Information Technology - Cabling Installation - Testing of
Installed Cabling (2002).
Electromagnetic Compatibility (EMC) Generic Standards Emission Standard for Residential, Commercial and LightIndustrial Environments.
Physical Layer Specification for 1000 Mb/s Operation on
Four Pairs of Category 5 or Better Balanced Twisted Pair
Cable (1000BaseT), July 1999.
Physical Layer and Management Parameters for 10 Gb/s
Operation.
Information Technology - Generic Cabling for Customer
Premises (2002).
Information Technology – Implementation and Operation of
Customer Premises Cabling. Part 1 – Administration. Part 2
- Planning and Installation. Part 3 - Testing of Optical Fibre
Cabling.
Flammability of a Single Vertical Cable.
Detail Specification for Connectors, 8 way. Test Methods
and Related Requirements for use at Frequencies up to 200
MHz.
Generic Specification for Testing of Generic Cabling in
Accordance with ISO/IEC 11801- Part 1.
Halogen Gas Emission.
Smoke Corrosivity.
Smoke Density and Evolution.
Information Technology – Generic Cabling for Customer Premises.
Commercial Building Telecommunications Cabling Standard
(2001).
Administration Standard for the Telecommunications
Infrastructure of Commercial Buildings.