Laboratory performance tests on aluminum splices for power conductors

Abstract

SUMMARYThe paper reviews the results of laboratory testing of compression and bolted splices installed on stranded aluminum power conductors. The tests on compression splices involved connectors of 10 different designs using 240 mm 2 stranded aluminum cable. Testing on the bolted splices was performed on connectors of 16 different designs installed on stranded aluminum cable with dimensions of 50 and 240 mm 2 . Splice performance was assessed on the basis of resistance measurements during short-circuit tests and thermal cycling as specified by the International Electrotechnical Commission (IEC) 61238-1 standard, and from inspections of cross-sectioned connections. Differences in splice performance are related to such factors as physical properties of the materials in contact, splice assembly procedures, number of compression indentations or number of bolts, and other relevant parameters. The influence of conductor deformation on the ability to disrupt aluminum oxide films on the conductor surface during connector installation is addressed. The laboratory data indicate that large mechanical deformations in a splice significantly improve connector performance. For compression splices, relatively soft (annealed) conductors lead to inferior performance than hard-drawn conductors, unless the soft conductor hardens significantly when it is deformed during installation. The sequence in which the compression indentations are made may influence connector performance.