Ensuring the Required Electrotechnical Properties during Recycling of Worn Trolley Wire

The paper presents information about the level of production of copper contact wires for trams and trolleybuses, their electrotechnical and strength properties, the most common shapes of wires used in transport. These wires are worn during operation; the initial shape is reduced in cross section, which decreases from 100 mm
²
or 85 mm
²
to 30 mm
²
. Recycling of the worn contact wire allows manufacturing copper wire of round and rectangular cross-section, which is in great demand in the tram and trolleybus depots. The technology of wire recycling consists of its rolling according to the rhomb-oval scheme and cold drawing with the drawing ratio of 1.14...1.31 in one pass. Rolling of round section with a diameter of 5.5...8.5 mm (depending on the initial wire cross section) is formed after 2...5 passes at a rolling speed of 2.04 m/min. Cold drawing allows making a round wire with a diameter of 1.2...7.5 mm and a wire of rectangular section (4 mm × 2 mm) from a round pre-rolled bars with diameter of 5 mm. Electrical resistivity, mechanical properties and microhardness allow to use the received wire for the manufacture of winding wire for electric brakes and motors coil and other electrical equipment.