Worker safety during various maintenance procedures common to underground residential distribution

The results of a high current test program studying worker safety during various common work procedures of underground residential distribution maintenance are presented. The tests involved maintenance procedures in and around below grade concrete vaults with interconnecting cables in buried PVC conduit. An elbow terminated each cable. A measurement of the voltage developed across the worker's body was made during each test and compared against a 50 volt allowed maximum. Procedures studied include the worker standing in the vault, standing near the vault, in contact with transformers connected in the vaults and while pumping water from a flooded vault.