bs英国标准bsen50288-1-20xx用于模拟和数字通信和控制的多元件金属电缆第1部分一般规范

bs英国标准bsen50288-1-20xx用于模拟和数字通信和控制的多元件金属电缆第1部分一般规范内容摘要：

al installation in ducts, trunking, suspended floors and ceiling cavities building backbone cable cable suitable for connecting a building distributor to a floor distributor and may also connect floor distributors in the same building. It is suitable for horizontal installation or vertical installation between floors provided the cable has adequate mechanical strength NOTE Horizontal cable as defined in may also be used as building backbone cable provided that it has adequate m echanical strength and fire performance characteristics. work area cable a cable connecting the telemunications outlet to the terminal equipment patch cord cable flexible cable unit or element with connector(s) used to establish connections on a patch panel NOTE W ork area cables , as defined in , may be used as patch cord cable in any dis tributor of a generic building wiring s ys tem to interconnect with equipment or to crossconnect between cabling s ys tems. EN 502881:2020 – 6 – campus backbone cable cable suitable for connecting a campus distributor to a building distributor(s). If used outdoors or for direct burial, it shall have adequate protection for its operational environment equipment cable a cable connecting equipment to a distributor instrumentation cable a multielement cable suitable for connecting instruments and control systems. It may incorporate screening, armouring and/or moisture barriers or environmental protection layers 4 Requirements for cable construction Conductors Conductors may be solid or stranded. The conductivity of copper conductors shall be in accordance with IEC 60028. Stranded conductors shall consist of wires circular in section and assembled, without insulation between them, by concentric stranding or bunching. As most of these cables are used together with insulation displacement connecting devices (IDC), a maximum of seven strands should be used. The solid conductors or the individual wires of stranded conductor may be plain or metalcoated. There shall be no joint in the wire made subsequent to the last wire drawing operation. Joints in individual strands of a stranded copper inner conductor shall be cold pressure welded, brazed or silver soldered using a non acid flux such that the strand diameter shall not be increased. No joint in an individual strand shall be within 0,3 m of a joint in any other individual strand. Insulation The choice of the insulating material shall take into account electrical and environmental requirements. The insulation material(s) shall meet the requirements of the relevant part or parts of EN 502902, or otherwise as detailed in the appropriate sectional specification. Conductor insulation shall be posed of one or more suitable dielectric materials. The insulation may be solid, cellular or posite (. foamskin). The insulation shall be continuous, having a thickness as uniform as possible. W hen required, the thickness of the insulation shall be measured in accordance with the method specified in of EN 6081111. – 7 – EN 502881:2020 The insulation shall be applied to fit closely to the conductor. W hen required, the stripping properties of the insulation shall be checked in accordance with the method specified in EN 50289317. W hen not used with IDC termination, it shall be possible to strip the insulation from the conductor easily and without visible damage to the conductor, its coating, or the insulation remaining on the conductor. Cable elements The cable element is a single insulated wire, or a pair consisting of two insulated conductors twisted together and designated wire “a” and wire “b”, or a triple consisting of three insulated conductors twisted together and designated wire “a”, wire “b” and wire “c” in order of rotation, or a quad consisting of four insulated conductors twisted together and designated wire “a”, wire “c”, wire “b” and wire “d” in order of rotation. W ires “a” and “b” form pair 1 and wires “c” and “d” form pair 2. The choice of the lay length of the cable elements in the finished cable shall take into account the transmission requirements, handling performance and identification. Identification of cabling elements W hen required, the insulated conductors shall be identified by colours and/or additional ring markings and/or symbols achieved by the use of coloured insulation or by a coloured surface using extrusion, printing or painting. Colours shall be clearly identifiable and shall correspond reasonably with the standard colours shown in HD 402. The colour(s) or the symbol used for core identification shall be durable such that it cannot be removed when tested to EN 5028938. Screening of cabling elements W hen required by the relevant sectional specification the cabling elements shall be screened by one or any bination of the following: a metal tape。 a metal tape laminated to a plastic tape。 a plain or coated metal braid。 a helical wrap of parallel copper wires。 a semiconducting layer. If a drain wire is incorporated, it shall be in contact with the screen element. The drain wire shall be either solid or stranded, made of plain or metal coated copper wire. Care should be taken when placing dissimilar metals in contact with each other. Coatings or other methods of protection may be necessary to prevent galvanic interaction. A protective wrapping may be applied under and/or over the screen. EN 502881:2020 – 8 – Cable makeup The cable elements may be laid up in concentric layers or in unit constructi。