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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 ...
A cable terminated according to T568A on one end and T568B on the other is a crossover cable when used with the earlier twisted-pair Ethernet standards that use only two of the pairs because the pairs used happen to be pairs 2 and 3, the same pairs on which T568A and T568B differ. Crossover cables are occasionally needed for 10BASE-T and ...
Linear heat detection (LHD) cable is essentially a two-core cable terminated by an end-of-line resistor (resistance varies with application). The two cores are separated by a polymer plastic, that is designed to melt at a specific temperature (commonly 68 °C for building applications [1]), and without which causes the two cores to short.
Some types of conduit are approved for direct encasement in concrete. This is commonly used in commercial buildings to allow electrical and communication outlets to be installed in the middle of large open areas. For example, retail display cases and open-office areas use floor-mounted conduit boxes to connect power and communications cables.
TS 54 -14 is a technical specification (CEN/TS) for fire detection and fire alarm systems (Part 14: Guidelines for planning, design, installation, commissioning, use, and maintenance). Technical Committee CEN/TC72 has prepared this document as part of the EN 54 series of standards.
Cables intended for direct burial must consider damage from backfill or dig-ins. HDPE or polypropylene jackets are common for this use. Cables intended for subway (underground vaults) may consider oil, fire resistance, or low smoke as a priority. Few cables these days still employ an overall lead sheath.