Sequential Mechanical Testing of Conductor Designs

Like many utilities, American Electric Power (AEP) has concerns regarding the longevity of new high temperature low sag conductors using non-traditional materials. For example, conductor designs such as ACCC (Aluminum Conductor Composite Core) and ACCR (Aluminum Conductor Composite Reinforced) that have entered the market in recent years as well as other new conductor designs that may be coming in the future. While vendors of the new conductors generally run their product through individual tests such as sheave, galloping, aeolian vibration, etc., they typically do not run a single sample through a sequence of tests to represent the mechanical loadings that generally occur during installation and operation of an actual line. For example, conductor installation (sheave testing), exposure to galloping conditions, aeolian vibrations and tension cycles due to varying weather loads. AEP has developed a testing protocol with the goal of evaluating new conductor designs in a few months (approx. 90 days) rather than having to wait years. In order to verify that the testing protocol is not excessively burdensome, AEP has partnered with Alcan Cable and Kinectrics to run samples of commonly used Drake ACSR (Aluminum Conductor Steel Reinforced) and Drake ACSS (Aluminum Conductor Steel Supported) through the same protocol. The only difference between ACSR and ACSS is that ACSR is stranded using hard-drawn aluminum wires, while in ACSS the aluminum wires have been annealed to remove any hardness and strength due to the wire drawing process. This paper discusses the findings of the test program. See Table 1 for the conductor properties.