An investigation of welded and cast joints for A.C.S.R. conductors

In the conventional joints for aluminum core steel reinforced (A.C.S.R.) conductors the path of the electric current in the outer strands passes through two mechanical contacts, while for the inner strands the number of contacts is considerably more. It is recognized that the present techniques of making compression Joints is considered by many to be satisfactory. However, it is obvious that a continuous metal Joint would be superior. Recent advances in welding make the construction of such a Joint possible. In the Joints constructed for experimental purposes each strand of a 397,500 C M conductor was brought out between two aluminium sleeves and Heliarc welded. In the finished Joint the weld bonds the inner and outer sleeves and the Individual conductors. The ends of the joint are compressed to prevent ingress of moisture which may be injurious to the conventional steel compression sleeve which connects the steel cores together. Tests of the Individual strand resistance as measured between the central part of the Joint and the strands showed the strand resistances to be uniform and equal to an equivalent length of strand. This shows that each strand was satisfactorily connected at the weld. Overall resistance, heat and mechanical tests indicate that the welded-compression joint should be satisfactory in the field. In addition to the welded-compression joint two cast-aluminium Joints were also investigated. These, however, due to poor bonding were found unsatisfactory.Applied Science, Faculty ofMechanical Engineering, Department ofGraduat