Specification, performance, testing and qualification of extra-heavy-duty connectors for high-voltage applications

The reliability of substation connectors is a constant concern for electrical utilities and represents one of the weak links of Hydro-Quebecʹs 735 kV power system. This paper describes some of the early findings of current-cycling tests on 4000 kcmil aluminum cable connectors and defines the need for more stringent qualification test specifications. Use of the ANSI C119.4 light-duty (125 cycles) test specification revealed a strong dependency on basic parameters such as surface roughness, dimension, type and surface finish of hardware, surface preparation, mounting techniques, etc. The first batch of test samples failed dramatically at an early stage in the current and load cycling tests. Some recommendations are formulated.