【導(dǎo)讀】EN50288-7:2020.interestsinformed;StandardsOnline.NORMEEUROP?ENNE. EUROP?C￢blesm?talliques￠?l?ments. multiplesutilis?riquesPartie7:Sp?cificationinterm?etdecontr?le. undKontrollkabelf?ranaloge. unddigitale?bertragung. f?

　　

【正文】 le or double layer of steel or brass tapes is used, the minimum thickness of tape shall be 0,20 mm for steel and 0,075 mm for brass. 11 EN 5028 8 7 :2 0 0 5 When a metal braid is specified the minimum wire diameter shall be 0,30 mm. The minimum filling factor shall be 0,57 when calculated as Annex B. Metal braid wire diameters are given in Annex C. Integral suspension strand Not applicable. Outer sheathing The outer sheathing material shall be appropriate to the operating environment and may be selected from the materials listed below. It shall be applied in accordance with of EN 502881: a) PVC to EN 50290222。 b) Polyethylene to EN 50290224。 c) Halogen free flame retardant pound to EN 50290227. The nominal thickness (SRt) shall be calculated in accordance with the following formulae: a) without metallic protection SRt = 0,04 x D + 0,7 mm (min 0,8 mm) b) with metallic protection SRt = 0,028 x D + 1,1 mm (min 1,3 mm) where D is the diameter under the outer sheath calculated in accordance with Table . For cables without metallic protection, the minimum thickness at a point shall not fall below the nominal value by more than 15 % + 0,1 mm. The minimum average thickness, rounded to 0,1 mm, shall not be less than nominal thickness. For cables with metallic protection (), the minimum thickness at any point shall not fall below the nominal value by more than 20 % + 0,2 mm Fauna protection When fauna protection is required, the method used shall be chosen from those in of EN 502881. There are no dimensional requirements. Chemical and /or environmental protection When chemical or environmental protection is required, one of the following methods shall be used. EN 5028 8 7 :2 0 0 5 12 Lead sheath The lead sheath shall ply with EN 50307. The nominal thickness (LRt) of the lead or lead alloy sheath shall be calculated using the following formula: LRt = 0,03 x D + 0,7 mm (min of 0,8 mm) where D is the diameter under the lead sheath, calculated in accordance with Table . The minimum thickness at any point shall not be less than 0,95 LRt ? 0,1 mm. Multi layer sheath The multi layer sheaths shall prise a laminated sheath (see ) and an additional layer of polyamide. The laminated sheath sheath shall consist of a logitudinal overlapped aluminium foil with an extruded layer of high density polyethylene according to EN 50290224. The thickness of the polyethylene layer shall be calculated as in with a minimum thickness of 1,0 mm. The thickness of the aluminium foil shall be at least 0,15 mm without coating. The coating may be on one or both sides. The thickness of the polyamide covering shall be at least 0,3 mm at any point irrespective of cable diameter. NOTE A material specification for polyamide is under consideration. 5 Test methods and requirements for pleted cables The following tables give the tests to be applied, together with the respective limits, in order to demonstrate pliance with this specification. 13 EN 5028 8 7 :2 0 0 5 Electrical tests Lowfrequency and . electrical measurements EN 502881 Clause No. Parameter Test method Requirement Conductor resistance EN 5028912 HD 383 for multicore cables and maximum shall be increased by 2 % for multipair, multi triple, and multiquad cables. Conductor resistance unbalance EN 5028912 N/A Dielectric strength EN 5028913 Duration 1 minute. For 90 V rating ? 0,75 kVac or ? 1,5 kVdc For 300 V rating ? 1,0 kVac or ? 2,0 kVdc For 500 V rating ? 2,0 kVac or ? 3,0 kVdc Insulation resistance EN 5028914 Material Resistance M?/km PVC 10 Polyethylene 1 000 Polypropolene 1 000 HFFR 10 XPLE 1 000 Mutual capacitance EN 5028915 Polyolefin 150 nf/km Others 250 nf/km Capacitance Unbalance (pairs/quads) EN 5028915 Polyolefin 500 pf/500 m Inductance EN 50289112 Only to be used for L/R Inductance to resistance ratio (L/R) EN 50289112 EN 502891 2 25 ?H/? for up to 1 mm2 40 ?H/? for 1,5 mm2 60 ?H/? for 2,5 mm2 Mechanical tests EN 502881 Clause No Parameter Test method Requirement Conductor elongation at break EN 5028932 10 % Shrinkage of insulation EN 5028934 EN 502881 Crush resistance of the cable EN 5028935 N/A Impact resistance of the cable EN 5028936 N/A Abrasion resistance of the sheath marking EN 5028938 N/A Simulated installation testing of the cable EN 5028937 N/A Tensile performance of the cable EN 50289316 N/A EN 5028 8 7 :2 0 0 5 14 Environmental tests For further study (ffs). Fire performance test methods Fire performance test methods shall be in accordance with of EN 502881. 15 EN 5028 8 7 :2 0 0 5 Annex A (normative) Insulation or sheath thickness and concentricity Selection of samples and evaluation of results Procedure for the measurement of thickness The thickness of an insulation or sheath shall be measured in accordance with and of EN 6081111. Three samples shall be taken from the cable at locations separated from each other by a distance of at least 1 m. Compliance shall be checked on 10 % of all cores of a cable with at least at a minimum all cores of one cabling element. If withdrawal of the conductor is difficult, it shal