ELECTRIC CABLES

摘要

A mineral-insulated parallel type heating cable has at least two copper or other high conductivity busbars and a plurality of separate heating elements each confined to a zone of the cable short compared with its total length (e.g. around 0.5-1.5m). Each of the heating elements is made up of a plurality of sections of metallic high resistance material which extend longitudinally (physically parallel) and connected electrically in series, while the element as a whole is connected across the two busbars. The preform for making the cable is preferably assembled by a technique using insulating material in preformed blocks.