TIA 569A Specification  

From our experience space is often overlooked when designing IT Network Infrastructures for Commercial Buildings. Below we have summarised the EIA/TIA-569-A Pathways and Spaces Standard which most North American readers will probably be familiar with but few UK readers.

Equipment Rooms

General design considerations

A single centralised space housing telecommunications equipment that serves a building.

• common equipment may include a PBX, computing equipment such as a mainframe and video switches

• only equipment directly related to the telecommunications system and its environmental support system is to be housed in the equipment room 

• ideally, the equipment room should be located close to the main backbone pathway to allow for easier connected to the backbone pathway

 Sizing issues

An equipment room is sized to meet the known requirements of specific types of equipment.

•  expected future requirements should also be considered

Equipment room design should allow for non-uniform building occupancy.

• the recommended practice is to provide 0. 07 m² of equipment room space for every 10 m²  of usable floor space (work areas.

• if work area density is expected to be greater, provide more equipment room space Multi-tenant building may have a single equipment room housing equipment of all tenants, or each tenant may have individual equipment rooms dedicated to their own equipment.

• there is also a factor which should be included for the equipment room size calculation to encompass modern LAN based Building Management Systems (see BMS Chapter in BiCSi Telecommunications Design Manual for details)

Special use buildings (hospitals, hotels, etc.) should have equipment room space calculated on the basis of the known number of work areas - not the usable floor area. Special consideration should be given to Dealer Rooms.

• Equipment room sizing is recommended as follows to allow for enclosed equipment cabinet traditional solutions:

 Other equipment room design issues

Ensure the floor loading capacity is sufficient to bear both the distributed and concentrated load of installed equipment.

The equipment room should not be located below water level; preventative measures should be taken to prevent water infiltration.

Consider also the following:

• sources of electromagnetic interference, vibration, room height, contaminants, sprinkler systems, HVAC equipment dedicated to the equipment room, interior finishes, lighting, power, grounding, fire prevention

Note: More Detailed information can be obtained from EIA/TIA-569 standard.

Telecommunications Rooms/Closets

General design considerations

The location of the Telecommunications Room should be as close as practical to the centre of the floor area to be served.

It is preferred to locate the TR in the core area

Closet space should not be shared with electrical installations.

Size and spacing issues

It is recommended to have at least one TR per floor; additional TRs are recommended when:

• the usable floor area to be served is greater than 1000 m²

• there should be one TR per 1000 m² of usable floor space

• a rule-of-thumb estimates usable floor space at 75% of total floor space

• the length of the horizontal distribution cable required to reach the work area is greater than 90 m (295 ft)

When there are multiple TRs on a single floor, it is recommended to interconnect these multiple closets with at least one conduit (trade size 3) or equivalent.

Assuming one work area per 10 m² the TR should be sized as follows:

Other TR design issues

Floor loading is to be at least 2.4kPa (50 lbf/ft²).

Two walls are to be covered with 2.6 m (8 ft) high, 20 mm (314 in) fire rated plywood to attach equipment.

Sufficient lighting is to be provided; wall, floor and ceiling finishes should be light in colour to enhance room lighting.

No false ceilings.

For powering equipment, at least two dedicated duplex electrical outlets on separate circuits are to be provided; for convenience, duplex electrical outlets should be placed at 1.8 m (6 ft) intervals around perimeter walls.

There are instances when it is desirable to have a power panel installed dedicated to serving the TR

Closet penetrations-sleeves, slots, horizontal pathways-must be properly fire-stopped as per applicable codes.

Security and fire protection are to be provided.

It is recommended to have continuous HVAC-24 hours per day all year round.

Notes on TR’s:

1.    More detailed information can be obtained from EIA/TIA-569

2.   In the UK/Europe where historically fully enclosed equipment cabinets have been used to mount equipment and connecting hardware, there is not normally a requirement for plywood faced walls. Whereas historically in North America connecting blocks have been wall mounted in TR’s using 110, 66 or BIX blocks which requires the plywood faced walls.  Also in North America equipment is often mounted in open 19” frames and this necessitates that these be housed in a closet/room.

3.    In some instances in UK/Europe one will find that in smaller installations the TR is not actually a self-contained room/closet.  This approach is often due to space/cost issues which can be overcome because in UK/Europe fully enclosed, securely locked equipment cabinets are extensively used. An example of this room/closet-less ‘Floor Distributor’ (term used in ISO11801) may consist say of one/two floor standing 42U high x 800 mm wide x 800 mm deep equipment cabinet/s located centrally within an open plan office. Great care must be taken if this closet-less  un-recommended approach is used primarily with respect to life-safety, and expertise should be sought. E.g. Fire Officer, BICSI RCDD, Office Space Planner.

Underground interbuilding backbone pathway

An underground pathway is considered to be a component of the entrance facility.   Pathway planning must consider the following: . limitations as dictated by the topology; this includes land development . grading of the underground pathway to permit proper drainage and the need to vent gaseous vapours

the amount of vehicle traffic to determine the amount of cover over the pathway and whether or not concrete encasement is required

Underground pathways consist of conduits, ducts and troughs; possibly including manholes.

All conduits and ducts are to have a diameter of 100 mm (4 in)

Bends are not recommended; if required there should be no more than two 90 degree bends

Direct buried interbuilding backbone pathway

A direct buried pathway is considered to be a component of the entrance facility.

In such cases, the telecommunications cables are completely covered in earth

Direct burial of telecommunications cables is achieved by trenching, auguring or boring [pipe-pushing].

• ploughing is not covered by the EIA/TIA 569 standard

When selecting a route for the pathway, it is important to consider the landscaping, fencing, trees, paved areas and other possible services.

Aerial interbuilding backbone pathway

An aerial pathway is considered to be a component of the entrance facility.

In such cases, the facility consists of poles, cable-support strand and support system.

Some considerations to make when using aerial backbone include the following:

• appearance - including the building and surrounding areas

• applicable codes

• separation and clearances for electrical and roads

• span length, building attachments, storm loading and mechanical protection

• number of cables currently and future growth potential

Tunnel interbuilding backbone pathway

Tunnel pathways can be made of conduit, trays, wire-ways or support strand.

The location of pathways within a tunnel must be planned to allow for accessibility as well as for separation from other services.

Intrabuilding backbone pathways

Vertical backbone pathway

Made up of vertically aligned telecommunications closets.

• closets located on separate floors are connected with sleeves or slots

Lift shafts are NOT to be used to locate backbone pathways.

Horizontal backbone pathway

If a telecommunications closet can not be vertically aligned with the one above or below.   Or if a closet cannot be vertically aligned with the entrance facility, then a horizontal backbone pathway is used to connect them.

Design issues

When using conduit (100 mm dia) or sleeves, the following amount of backbone pathway is recommended:

• one sleeve or conduit per 5000 m² of usable floor space to be served by that backbone system

• in addition, two spare sleeves or conduits for a total of at least three.

Horizontal Pathways

Under floor duct

A system of rectangular distribution and feeder ducts; a network of raceways embedded in concrete.

Distribution ducts - are those ducts from which the wires and cables emerge to a specific work area.

Feeder ducts - are those ducts which connect the distribution ducts to the telecommunications . closet.

For general office use, the practice is to provide 650 mm² of cross-sectional under floor duct area per 10 m² of usable floor space-this applies to both distribution and feeder ducts.

This is based on the following assumptions:

• three devices per work area

• one work area per 10 m²

Access floor

Made up of modular floor panels supported by pedestals with or without lateral bracing. - used in computer and equipment rooms as well as general office areas it is necessary to design floor penetrations for the type and number of work areas.

• penetrations may be located anywhere on the access floor

• service outlets must not be placed in traffic areas or other areas where they may create a hazard to the occupants

Conduit

Conduit types include electrical metallic tubing, rigid metal conduit and rigid PVC.

• the type of conduit used must be permitted under the appropriate electrical codes • metal flex conduit is not recommended due to possible cable abrasion problems Using conduit for a horizontal raceway system for telecommunications cabling should be considered only when:

• telecommunications outlet locations are permanent

• device densities are low

• flexibility is not a requirement

Installed conduit has requirements for support, end protection and continuity as specified in appropriate electrical codes.

• no section of conduit can be longer than 30 m (100 ft)

• no section of conduit can contain more than two 900 bends between pull points or pull boxes

Cable trays and wire-ways

These are rigid structures for the containment of telecommunications cables.

• prefabricated structures consisting of side rails and a solid or ventilated bottom

Trays and wire-ways can be located above or below the ceiling in plenum or non-plenum applications.

For general office use, the practice is to provide 650 mm²  of cross-sectional tray or wire-way area per 10 m² usable floor space or work area.

This is based on the following assumptions:

• three devices per work area - one work area per 10 m²

Ceiling pathway

Conditions for ceiling distribution systems include the following:

• inaccessible ceiling areas [lock-in ceiling tiles, drywall, plaster] are not to be used as distribution pathways

• ceiling tiles must be removable and placed at a maximum height of 3.4 m (11 ft) above the floor

• there must be adequate and suitable space available in the ceiling area for the recommended distribution layout-a minimum of 75 mm (3 in) of clear vertical space must be available

• there must be a suitable means and methods for supporting cables and wires-they are not to be laid directly on the ceiling tile or rails.

• raceways are to be provided where required by codes or design

Perimeter raceways

Used to serve work areas where telecommunications devices can be reached from walls at convenient levels.

The determining factor for using perimeter pathways is room size.

• all devices in the room depend on services from fixed wall areas

• practical capacity for perimeter raceways is 30% to 60% fill depending on cable-bending radius

Not covered by standard

Over-floor raceways

Exposed wiring

Poke-thru

Curtain wall

Work Area

Work areas

Recommendations for work areas cover only specifications for telecommunications pathways and telecommunications outlets.

Work area telecommunications pathways

Furniture pathways

• if telecommunications pathways are to be incorporated into furniture or partitions, they must comply with:

• all applicable electrical codes

• UL 1286, "Office Furnishings"

• manufacturers should be consulted to determine raceway capabilities and optional features available.

Reception areas, control centres, attendant areas

• these areas typically have heavy demands for telecommunications equipment

• it is recommended to have independent, direct pathways to these areas from the telecommunications closet

Telecommunications outlets

A typical example of such a connection point is a 100 x 100 mm (4 x 4 in...in USA much smaller in the UK) electrical box with horizontal cable terminated on faceplate connectors.

• telecommunications devices in the work area are connected to the faceplate It is necessary to consider the number and type of devices to be connected.

• typical telecommunications devices include telephones, personal computers, graphic or video terminals, fax machines, modems

At least one outlet box should be provided to each work area.

*for areas where it will be difficult to add telecommunications outlet boxes at a later time, at least two separate outlets are recommended for initial installation; to maximise flexibility they should be located to allow for a change in office design [e.g. locate outlet boxes on opposite walls]