Structured Cabling System
Equipment room
The equipment room (ER) houses telecommunications systems, such as PBXs, servers, routers, switches, and other core electronic components as well as the mechanical terminations.
It’s different than the telecommunications room because of the complexity of the components.
An equipment room may take the place of a telecommunications room or it may be separate.
It can also function as the entrance facility. The equipment room is specified in TIA/EIA-568-B.
Design recommendations are in TIA/EIA-569-B.
Design considerations.
• Each building should contain at least one equipment room or telecommunications room.
• Only install equipment related to the telecommunications system.
• Consider future expansion when sizing and placing the equipment room.
• Design the door to accommodate the delivery of large enclosures and equipment. The door should be a minimum of 910 mm (35.8 in.) wide and 2000 mm (78.7 in.) high. A double door without a center post is best.
• The minimum ceiling height shall be 2.4 meters
(7.8 ft.). No false ceilings either.
• The minimum recommended size is 14 m 2
(150.7 ft.
2 ). The general rule is to allow 0.07 m 2
(0.75 ft.
2 ) for every 10 m 2 (107.6 ft.
2 ) of usable floor space.
• The room should have conditioned power and backup power.
• Protect against vibration, EMI, contaminants, and pollutants. The room should not be near mechanical rooms, electrical distribution panels, and wet/dirty areas.
• Take into account any water infiltration issues.
Do not locate the room below water level.
• Like the telecommunications room, provide
24/7/365 HVAC. Temperature and humidity should be controlled.
• The lighting should be the same as the TR:
500 lux (50 foot candles).
• The floor loading should be a minimum of 4.8 kPa (100 lbf/ft 2 ).
Entrance Facility and Equipment Room
Entrance facility main cross-connect
Equipment room main cross-connect
Telecommunications room
Backbone cabling
Backbone cabling
Telecommunications room
Entrance facility
The entrance facility (EF) is the point where the outdoor plant cable connects with the building’s backbone cabling. This is usually the demarcation point between the service provider and the customerowned systems. The entrance facility is designated in TIA/EIA-568-B. Design recommendations are in
TIA/EIA-569-B. It includes:
• Cables.
• Connecting hardware.
• Protection devices.
Design considerations.
• The entrance facility may also house the backbone links to other buildings in a campus.
• Public network interface equipment and telecommunications equipment may be in the entrance facility.
• The location should be a dry area, near the vertical backbone pathways.
• The entrance facility should be provisioned as the telecommunications room is for environment, HVAC, lighting, doors, electrical power, etc.
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Building Pathways
Backbone pathways
Pathways
Simply put, a pathway is the space in which cable runs from one area to another. The standard
TIA/EIA-569-B: Commercial Building Standard for
Telecommunications Pathways and Spaces defines different types of pathways, such as interbuilding, intrabuilding, horizontal, service entry, etc.
This discussion will cover intrabuilding backbone and horizontal pathways. Interbuilding and service entry pathways are beyond the scope of this guide.
Equipment room
Horizontal pathways
Telecommunications room
Work area
Entrance facility
Intrabuilding backbone pathways.
Intrabuilding backbone pathways run vertically and horizontally between the entrance facilities, equipment room, and telecommunications room(s).
They carry the backbone cable and can be conduit, sleeves, slots, or cable trays. Complete specifications for conduit, sleeves, trays, pull points, and more can be found in the TIA standard.
NOTE: Make sure all pathways are firestopped.
And, do not use elevator shafts as backbone pathways.
Vertical backbone pathways. When designing a building, stack the telecommunications rooms vertically above one another on each floor. This provides for the easiest and most efficient backbone runs. The TRs should have a minimum of three 4-inch sleeves for floor areas of 5000 m 2 (58,819 ft.
2 ). One sleeve is for the cable; the other two are spares.
Horizontal backbone pathways. If the TRs are not stacked vertically, use 4-inch conduit to connect them horizontally. You should have no more than two 90° bends between pull points. In addition, the fill should not exceed 40% for any run greater than two cables.
Horizontal pathways.
As the name suggests, these pathways run horizontally between the telecommunications room and the work area. You can choose a number of different pathways, depending on your facility, office layout, and cable type. When choosing, keep in mind the pathway fill for current and future use, and allow enough room for growth.
Pathway options.
Underfloor duct. These are a system of single- or dual-level, rectangular ducts embedded in concrete flooring that’s at least 64-mm (2.5-in.) or 100-mm
(3.9 in.) deep, respectively.
Flush duct. This is a single-level, rectangular duct embedded flush with the top level of a 25-mm (1-in.) concrete surface.
Multichannel raceway. Ducts have separate channels for running telecommunications and power cable. The raceways are designed to be buried in
75-mm (3-in.) reinforced concrete.
24 Black Box Guide to Structured Cabling
