System Listings

Data & Communication Systems  

System Overview
Data and communication systems form a major part of the installation requirements in a modern building. The systems are increasingly complex and are relied upon to help manage and run nearly all commercial and industrial premises.

The systems under consideration include:

• Telephone systems
• In house communications such as intercom systems
• Data networking (computer networks)
• Building Management Systems (BMS)

It is not intended to extensively detail each system here, rather to present an idea of the considerations that must be borne in mind when facilitating such systems.

It is normal for the building services designer to design only the cable containment systems and power requirements for such systems. Communication system design is a specialist area, is being constantly undated, and hence requires specialist knowledge of the latest equipment and systems.

Whatever the form of data & communication system to be installed, they all have some specific requirements in common. Usually as follows.

• Cabling is extra - low voltage and must hence be properly segregated from 240V and other mains services.
• Cabling is often fragile and so must be properly protected against mechanical damage.
• Cabling is often extensive (particularly modern structured wiring) hence adequate room must be allocated to the cable runs.
• Consideration should be given to using cable tray, cable basket or trunking as required. In particular, the use of multi-compartment containment systems is common. This enables various services to be brought to the same location. 

Systems Available and Applications

•   Telephone systems.- These systems generally emanate from a central equipment room (often the comms room). Normally, a number of incoming telephone lines (BT, Cable, Mercury etc..) will terminate in the comms room and are connected to the telephone internal exchange equipment. This may be referred to as PABX equipment etc. At this point, links will be made to internal control points such as the main telephone exchange or operators room, front reception desk or other central control point.
  Telephone system wiring may emanate directly from the PABX unit and be terminated on to Test Jack Frames (TJF) from where multi-pair telecommunication cables (often classed as CW1308) run throughout the building.
  Large multi-core cables will normally rise through the building with smaller branches being made to telephone equipment and outlets on each floor or building area.
  Different wiring methods may be used. In particular, the use of structured cabling is now extremely common.
•  In house communication (intercom) systems. - These systems generally comprise a system of wall or desk mounted handsets connected together by multicore cabling. Handsets enable other units to be called and enable cheap easy verbal communication throughout a building. In past years these systems operated independently from the telephone systems, with cabling being run often in to similar locations.
  In recent years telephone systems have become more complex and are now normally able to provide internal communication functions including hands free operation and single touch dialling ect...
  Variants of the conventional intercom system are commonly used for door access systems and simple security applications. 
  
• Call systems.  - These systems are usually independent and may or may not include some form of speech facility. A common application of call systems is in disabled toilet facilities, where pullcords and/or buttons are provided at low level to facilitate wheelchair users. In the event of an emergency or problem, activation of the pull cord or switch will sound a buzzer and energise a flashing light outside the WC hence gaining attention of passers by. The system is only able to be reset from within the WC.
  Larger more complex systems are common in nursing facilities, residential care homes and hospitals. 
  
•  Data systems - These systems will usually link desktop computers throughout the building both with themselves and to outside networks. Clearly the type of system is wholly dependent upon the nature of building use and the type of business performed by the occupants. However, data system (whatever type) will usually originate at a main central communications room. Here the main computer processing equipment will be housed (servers, mainframes etc.)
  Wiring will run throughout the building from this point, the type of wiring, method of connection and distribution being wholly dependent on the type of system. Fibre optic cabling may be used as well as many different forms of data cables. Many specific arrangements of data networking exist - most are implemented by specific manufacturers.
  In recent years the concept of structured wiring has become increasingly common. This is increasingly becoming a standard method of wiring.
  When facilitating data cabling the electrical designer must be fully aware of the following:
  • Number of cables at a given location
  • Size of each cable
  • Bending radii of cables
  • Environmental requirements of cables (ie: can they be run outside etc..)
  • Insulation characteristics of cables
  • Smoke emission characteristics of cables
    
•  Building Management Systems (BMS) . The BMS system has become an common method of controlling the mechanical and electrical services systems within the building. The BMS generally comprises a network of outstations which all connect to a central control station (typically using fibre optic cabling). From each outstation, field wiring in the form of data cabling, runs to sensors, valves and control elements. The BMS system may include links to fire alarm systems, air conditioning, ventilation systems, lighting, heating and more recently electrical distribution  systems. All functions of the building services can hence be monitored and automatically controlled.
  BMS cabling must be carefully coordinated with other services and it must be ensured that termination points are accessible (they are often forgotten about, being behind panels, ceilings and plant) 
• Structured cabling systems. Structured cabling systems represent a "standard" way of wiring data and communication systems. Structured wiring is a relatively recent introduction, and takes advantage to the increasing convergence of technologies apparent when comparing telephone and data networking systems.
  At its simplest, a structured wiring systems comprises the following.
  
  Wiring Cabinet. A central wiring cabinet or hub which has communication inputs from various sources such as a telephone PABX system, a main computer server and similar equipment.Within the wiring cabinet are intelligent modules which enable the various inputs to be converted to a standard form of output (in terms of voltage)
  
   Cabling.  Radiating from the cabinet, standard cables run to equipment and accessories throughout the building. Cabling is called Category 5 UTP (UnTwisted Pair)  and is wired in a star fashion to all outlets, one cable per outlet.   
  
   Outlets. A common outlet is installed wherever an item of equipment is required. Outlets are called RJ45 outlets and are industry standard. The outlet is the same regardless of what type of equipment will be used (ie: telephone or computer). Outlets can match standard power accessories.
  
  Patch panel. Within the wiring cabinet, the relevant input systems are matched to the relevant cable termination depending upon what use the outlets is required for. Flexible connection cables are used to form a patch panel which is easily adaptable should an outlet ever be required to serve a different purpose.
  
  The system will often be more complicated than this, possibly several wiring cabinets may be used.
  The big advantage of such a system is its adaptability, also, the system can be installed without specific need to know exactly what equipment is needed in each area.
  The main disadvantage of structured cabling is the large amount of cables that are installed and significantly, the large amount of room they take up. Even small premises can require a large containment system to adequately house all the cables.  
  
• Power requirements. Data & communication equipment normally requires specialist power arrangements.This is due both to the sensitive equipment used and the buildings dependence on the systems. In particular, the use of UPS systems, clean earth and clean supplies must be considered.

Legislation & Guidelines
The design of data and communication systems is not covered below. for further information regarding system design requirements refer to The British Standards Institution

However, it is necessary to take account of relevant standards when specifying containment and power requirements for such systems

Always discuss the systems fully with the relevant parties to ensure all systems are correctly facilitated.  

British Standards.

Also refer to The British Standards Institution

• BS 7671:2001 "Requirements for electrical installations". IEE Wiring Regulations. Sixteenth edition. This is the all encompassing "Bible" in relation to the design, installation and use of electrical installations and equipment in buildings.It is relevant here due to the need to segregate LV cabling (which data cables normally are), also for the installation of associated controls and equipment.
• BS 4087: 1989" Specification for copper-covered steel wire for telephone and telegraph purposes". Mechanical and electrical properties of copper-covered steel wire with two grades of conductivity and three of tensile strength together with size tolerances for a range of wire sizes. Metric units.
• BS 4808: Specification for L.F. cables and wires with PVC insulation and PVC sheath for telecommunication

Combined Standards

• BS EN 50173:1996 "Information technology. Generic cabling systems" Specifies the generic requirements for communication cabling for use with commercial premises.
• BS EN 41003: 1993 =EN 41003:1993 "Particular safety requirements for equipment to be connected to telecommunication networks" Replaces BS 6301:1989.

International Standards

See also IEC search page

• IEC/TR2 61085 (1992-04) "General considerations for telecommunication services for electric power systems". Gives an overview of the specific problems and requirements for electric power utility telecommunication systems. Is published as a technical report.
• IEC 61156-1 (1994-07) "Multicore and symmetrical pair/quad cables for digital communications" - Part 1: Generic specification Is a guide to indoor cables which specifies the definitions and requirements of multicore, symmetrical pair and quad cables used in digital communication systems such as ISDN, local area networks and data communication systems.

Legislation

Refer also to the Her Majesty's Stationary Office (HMSO) Government Web Site for further items of legislation and literature.

• Health & Safety at Work Act 1974 - Massive item of legislation which encompasses all aspects of Health & Safety in the workplace. This has been constantly added to over the years. It now comprises and references a whole series of separate regulations and codes of practice documents.
• Electricity Act 1989 - In the words of the official HMSO title. "An Act to provide for the appointment and functions of a Director General of Electricity Supply and of consumers' committees for the electricity supply industry; to make new provision with respect to the supply of electricity through electric lines and the generation and transmission of electricity for such supply; to abolish the Electricity Consumers' Council and the Consultative Councils established under the Electricity Act 1947; to provide for the vesting of the property, rights and liabilities of the Electricity Boards and the Electricity Council in companies nominated by the Secretary of State and the subsequent dissolution of those Boards and that Council; to provide for the giving of financial assistance in connection with the storage and reprocessing of nuclear fuel, the treatment, storage and disposal of radioactive waste and the decommissioning of nuclear installations; to amend the Rights of Entry (Gas and Electricity Boards) Act 1954 and the Local Government (Scotland) Act 1973; and for connected purposes."
• Electricity at Work Regulations 1989 - Regulations covering the whole aspect of ensuring that the workplace is safe in regards to the use of electrical equipment. (a part of the H&S at Work act)
• Construction (design & management) regulations 1994 - Another wide reaching set of regulations which cover the whole process of construction safety. It focuses on carrying out risk assessments and altering the design or management process to account for such risks. Again this forms part of the H&S at work act 1974.

Related Links

Links relating to the design and installation of  data & communication systems can be found here

Manufacturers

Manufacturers of data containment system, data accessories and data cables are listed here