Control of conductors to prevent construction problems

The increases in cross-section and number of layers have gone hand in hand with new problems, chiefly with stringing conductors, e.g. the loosening of layers, which may lead to making birdcage, inter-layer slip connections difficult and, in general, problems which may, in extreme cases, mean that the conductors cannot be laid. With the conductor tests normally carried out, as indicated in the standards, it is not possible to calculate the conductor´s specifications as to its greater or lesser degree of loosening (stringing conductors problems). The study of the stringing conductors problems has been carried out using a new method based on traction-torsion tests so as to register the rotation moments in each layer according to the force applied. These tests also provide data on the distribution of forces between the conductor layers. The authors discuss the test procedure