Version: 1.0
Status: 8/26/99
Contact: Ron Olton
The Virginia Community College System has adopted a standard cabling and conduit plan for the campus. Over time, all buildings will come into compliance with the plan. The plan supports voice, data, and video communications for every room. This plan is particularly important in an engineering building due to the high degree of automation and the dependency on state of the art technology. The telecommunications infrastructure must be flexible and contain enough capacity to handle many technology changes over the life of the building. More and faster telecommunications of all types will require fiber optic cable and specialized electronics to drive the anticipated demands of the faculty in support of instruction and research.
New buildings require voice, data, and video wiring and electronics facilities within the building to support the newest forms of telecommunications. A series of standards has been developed to provide guidance in designing new buildings and remodeling older facilities. The list of facilities that need to be taken into consideration are building entrance facilities, entrance wiring closets, floor wiring closets protection and grounding, backbone raceways, horizontal raceways, backbone wiring, and horizontal wiring. A more definitive document exists which identifies the considerations and options for architectural and engineering areas supporting telecommunications within a building. The document should be used for design activities, as the following material is a summary.
Entrance facilities -- Cabling must enter the building underground and usually within 4 inch conduits. Three or more of the conduits will be required to connect an entrance wiring closet to the nearest manhole or other location with telecommunications facilities. Consideration is required for the type of conduit, depth of bury, separation from other conduits bends in the conduit, conduit capping and seals, manhole sizes, and pull lines.
Entrance wiring closet -- Exclusive use of a room for placement of electronics and terminations of cable of many types, which supply the building with telecommunications. Security is required and the room cannot be shared with other functions in the building. Considerations for the facility are floor weight load factors, water avoidance, lighting, electrical access, room size, electrical grounding, HVAC, and location near the building entrance facility.
Floor wiring closet -- Exclusive use of a location on each floor to facilitate the electronics and cabling distribution for the floor. If the floor is large enough, with long cable runs, more than one room may be required on each floor. Security requires that the room not be shared with other building functions. Considerations for the facility are floor loading factors, water avoidance, ceilings and walls, fire door, lighting, electrical access, room size, electrical grounding, HVAC, floor location, and cable run maximum lengths.
Backbone raceways -- Backbone raceways are a series of accesses that connect the entrance wiring closet to the various floor wiring closets. These paths permit cable to be placed between the floors. They may be slots, sleeves, conduits or trays and racks in which cables may be routed for support and protection. Considerations are the size, quantity, and seals. If conduits or sleeves are used, the 4 inch size is preferred. The in depth document contains a table giving the number of paths needed, based upon building size.
Horizontal raceways -- The horizontal raceway carries the cable from the floor wiring closet to the various rooms on the floor. There are many types of systems available today and the pros and cons of each are covered in the detail document. Ceiling trays used in conjunction with utility columns and conduit paths are the preferred method of horizontal distribution. The nature of the building usage may justify another type of cable path. Considerations for the path include bends or curves, size, conduit run lengths, and outlet boxes.
Cabling -- Entrance cables will include fiber optic and copper wire cables. These will be terminated in electronics inside the entrance wiring closet. From there, fiber optic, coax, and copper wire will be taken to each floor wiring closet. Terminations will connect to the electronics in the room. Coax, copper, and optionally fiber optic cables will run from the floor FMC to each room on the floor. Each room will have one or more boxes at the end of the conduit. Box face plates will contain the appropriate jacks for termination of the wiring. These jacks will be used to connect equipment inside the room to the network wiring system. The detail document covers the types of jacks, wiring sizes, etc.
The standards offered for use contain alternatives so that flexibility for the architecture and engineering requirements may take precedence. Flexibility and access to cable paths is the key to adaptability. In the future, labor costs for pulling new cables will continue to be more than the electronics and other costs. Rapid technology changes will require that the entrance and floor wiring closets, and the cable paths be revisited several times during the life of the building.
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Definition of Terms Used in the Specifications
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