Tables / Explanations AWG-Sizes - Prysmian Group

TABLES / EXPLANATIONS AWG-SIZESCore arrangementThe basic criteria of the core arrangement for flexibleelectric cables for cranes and material handlingequipment are summarized in the adjacent table.In round flexible electric cables, the individual coresare arranged by laying them up. Up to three coresare laid up without a central element. Four cores andabove are laid up around a centre, which can alsoconsist of three-core stranded elements.A stretched core in the centre of the flexible cable(as the actual centre or placed in the centre) is notpermitted according to the DIN VDE standards. Astretched core at the centre of the flexible cablewould quickly result in premature failure of theconductor due to breakage, especially in flexibleelectric cables for cranes and material handlingequipment.A maximum of three core layers is best for theconductor assembly. Investigations have shown that,if there are more than three layers, the internalstability of the flexible cable and in consequencethe service life is reduced as a result of increasingsecondary and relative forces between the cores.The length of lay S is a design feature used for layingup the conductor assembly (see table 4/28) andinfluences the bending flexibility and the bendingstability. The length of lay is an important factor forthe service life of flexible electric cables for cranesand material handling equipment.In the case of flat flexible cables, laying up is notusually necessary as the cores are arranged parallelto each other. Flat flexible cables with laid up bundlesrepresent an exception to this rule. This special formof core arrangement is selected for large numbers ofcores in order to ensure the required stability of theflat cables.Round flexible cable Round flexible cableTable 4/28Laying up of two to threecores without a centreLaying up of four or morecores with centre Specialdesign: the centre comprisesthree coresMaximum three-layerdesign (standard up to 56cores)A stretched core in thecentre of a flexible cable isnot permittedThe length of lay S is thelength, measured in thedirection of the lay, overwhich a core circumscribes360° around the layingaxis. It is given as a multipleof the diameter D overthe conductor assembly,e.g. S = 8 x D.Parallel arranged coresCores laid up in bundles(refer to round flexiblecables), parallel arrangedbundles