Some effects of mill practice on the stress strain behavior of ACSR

Operating temperatures of overhead lines have risen. Tests have indicated that conventional sag tension calculations may underestimate sags that occur at the higher temperatures in ACSR (aluminum conductor steel reinforced) spans. Search for the source of the disparities has identified two effects associated with the manner in which conductors are manufactured. One effect involves residual stresses, resulting from stranding practice, in the finished conductor. The other is caused by the ability of the aluminum part of ACSR to bear axial compression. Analysis of these effects appears to explain the disparity in at least one of the test programs that revealed it.