A field investigation of the effects of neutral separation and supplemental grounding on primary neutral-to-earth voltage levels

The authors present the results of a field investigation undertaken to examine how primary neutral-to-earth voltage levels on a rural distribution feeder are affected by the degree of primary neutral grounding and/or primary/secondary neutral separation. Separation of primary and secondary neutral/ground systems has been identified as one method for reducing potential off-farm voltage sources in studies of stray voltage problems at diary farms. The results of this study have shown that the present preferred method of solidly bonding primary and secondary neutrals is consistent with the goal of minimizing the primary neutral-to-earth voltage on rural feeders. The large amounts of supplemental primary neutral grounding provided for in this investigation, could not reduce the primary neutral-to-earth voltage to zero while the neutral was performing its intended function of serving the distribution load