Of ceramics

85.46 Electrical insulators of any material. 8546.10 - Of glass 8546.20 8546.90 - Of ceramics - Other Insulators of this heading are used for the fixing, supportin or guiding of electric current conductors while at the same time insulating them electrically rom each other, from earth, etc. insulating fittin s (other than insulators) for electrical machinery, these fittings fa 1in headin 85.47 if they consist who11 of insulating minor components of meta incorporated during rnoul mg solely for F f T B Usually there is a relation between the size of the insulator and the voltage (large for high voltages, smaller for low voltages). Similarly, the sha e of the various types of insulators is influenced by electric, thermic and mechanical consi erations. The external surface is very smooth in order to prevent the formation of deposits of non-insulating materials, such as water, salts, dusts, oxides and smoke. Insulators are often iven bell, accordion, petticoat, grooved, cylinder or other shapes. Certain types are constructe in such a way that when in posit~onthey may contain oil to prevent contammation of the surface by conducting materials. B f Insulators may be made of any insulating material, usually very hard and non-porous, e.g., ceramic material (porcelain, steatite), glass, fused basalt, hardened rubber, lastics or compounded insulating materials. They may contain fixing devices (e.g., meta brackets, screws, bolts, clips, laces, slings, ms, cross pieces, ca s, rods, suspension or canying clamps). Insulators equipped with metal oms or guard shie ds or other devices to form lightning arresters are excluded (heading 85.35). P < P power networks, electrical hsulators are used on outdoor cables, e. ., in telecornm~~~ications, traction systems (railway, tramway, trol eybus, etc.), and also for indoor installations or on certain machines and apphances. f The insulators of this heading include : (A) Suspension insulators, such as : (1) Chain suspension insulators. These are used mainly on outdoor networks, and consist of several lnsulatin elements. The conductor cable or wire is fixed at the bottom of the assembly which is ung on a suitable support (pylon arm,suspension cable, etc.). E Suspension chain insulators include cap or hood type insulators, double petticoat insulators; chain link insulators; linked rod insulators. (2) Other suspension insulators (e. ., insulators in the form of balls, bells, pulleys, etc.) for overhead lines of railways, tro leybuses, cranes, etc., or for aerials. (B) Rigid insulators. These may be fitted with sup orts (e.g., metal hooks, pins or the like); or they may be without supports, but intende to be attached to power or telegraph poles, etc., or fitted to walls, ceilings, floors, etc., by means of nails, screws, bolts, etc. Insulators with fixed supports may be built up of two or more elements; those without su ports are usually single units. They may be of various shapes (e.g., bells, cones, cylinders,%uttons,pulleys). dP (C) Leading-in insulators. These are used for ding cables or wires though walls, etc. They are of various forms (e.g., cone or doubgU1 e cone shaped insulators, disc insulators, sleeves, pipes and tubular bends). The heading excludes insulated electrical conduit tubing and joints therefor (heading 85.47).