Cables for data transmission in industrial automation - LEONI

www.leoni-industrial-projects.com Design options 69Mechanical and chemical protectionMechanical protectionThe primary purpose of armour is to protect the cable againstmechanical damage during installation and operation.The most common armour designs with their most importantfeatures are the following:A suitable protection can be achieved by corresponding measures:Armour of galvanised round steel wires (SWA)Chemical protectionIf the risk of oil and chemicals affecting the installed cablecannot be excluded this may affect the operation of the cablesin long term.The extent of the risk is determined by type, agressive nature,condition and quantity of the medium, the duration of immersionand the temperature.Lead sheath (M)Very good mechanical protection; reasonably good flexibility;suitable for tensile loads; coverage of over 90 %The safest, though most expensive protection against aromatichydrocarbons and active chemicals.Armour of galvanised steel wire braid (Q)Multilayer sheath ((L)2Y4Y)Lightweight armour to withstand tensile loads; permits thesmallest bending radii of all armour designs; used mainly forsmall cable diameters; a coverage of at least 80 % and a wirediameter of 0.3 mm are recommended to achieve sufficientmechanical protectionSame as lead protection against aromatic hydrocarbons andactive chemicals. This design combining aluminium tape andhigh density polyethylene HDPE sheath with a covering ofpolyamide PA (Nylon), represents an excellent barrier againstpenetrating chemicals and can be used as an alternative tolead sheath. Advantage: lighter, smaller diameter.Armour of corrugated steel tape (SR)Oil resistant PVC sheath (Yö)In contrast to standard PVC (Y) this compound is moreresistant to oils and aliphatic hydrocarbons. It passes the oilresistance testaccording to IEC 60811-2-1.100 % covering of the cable assembly; good protection againstrodents.