Field Trials on 15-kV and 600-Volt Sodium Cable

The use of sodium conductor cable presents an opportunity for reduction in cost of cable for underground residential distribution systems. In order to evaluate its usage a direct buried test installation was made involving both 15-kV and 600-volt sodium cable. Testing the 15-kV cables consisted in load cycling, short-circuit faulting, and fault location tests. After the completion of tests on the 15-kV sodium cable, a service installation was made in a rural area west of Chicago. Load cycle tests were also made on the 600-volt sodium cable. This included an overload which resulted in the failure of the cable at the terminal. Insulation damage tests were made to determine the corrosive properties of the conductor. Fault locating tests made on the 600-volt cable, as on the 15-kV cable, showed that presently available equipment should be adequate.