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Diagram of a direct-buried cable: Date: June 14 2007 (original upload date to wp was 2006-12-19) Source: self-made, based on image from en.wikipedia (description page is/was here). Author: SVG by Editor at Large, original creator was Elaragirl: Permission (Reusing this file) Original was published as {{GFDL}} and {{GFDL-self-with-disclaimers ...
Cross-section of direct buried cable. Direct-buried cable (DBC) is a kind of communications or transmissions electrical cable which is especially designed to be buried under the ground without any other cover, sheath, or duct to protect it. [1] Most direct-buried cable is built to specific tolerances to heat, moisture, conductivity, and soil ...
Directional boring, also referred to as horizontal directional drilling (HDD), is a minimal impact trenchless method of installing underground utilities such as pipe, conduit, or cables in a relatively shallow arc or radius along a prescribed underground path using a surface-launched drilling rig. Directional boring offers significant ...
A utility tunnel, utility corridor, or utilidor is a passage built underground or above ground to carry utility lines such as electricity, steam, water supply pipes, and sewer pipes. Communications utilities like fiber optics, cable television, and telephone cables are also sometimes carried.
While metal conduit is occasionally used for burial, usually PVC, polyethylene or polystyrene plastics are now used due to lower cost, easier installation, and better resistance to corrosion. Formerly, compressed asbestos fiber mixed with cement (such as transite) was used for some underground installations. Telephone and communications ...
Cable type TC is especially intended for use in tray systems. Special wiring rules apply to wet or corrosive locations, [ 13 ] and to locations which present an explosion hazard. [ 14 ] Wiring materials for use in the United States must generally be made and tested to product standards set by NEMA and Underwriters Laboratories (UL) and must ...
Diagram of a simple electrical cable with three insulated conductors, with IEC colour scheme About 1950, PVC insulation and jackets were introduced, especially for residential wiring. About the same time, single conductors with a thinner PVC insulation and a thin nylon jacket (e.g. US Type THN, THHN, etc.) became common.
To reduce this loss these antennas often use a conductive copper ground screen under the antenna connected to the buried ground wires, either lying on the ground or elevated a few feet, to shield the ground from the electric field. In a few cases where rocky or sandy soil has too high a resistance for a buried ground, a counterpoise is used. [11]