Field trials of Cutout mounted reclosers on single-phase spur lines in ESB networks, Ireland

The high proportion of rural overhead networks comprised of single-phase spurs (laterals) and the high proportion of interruptions due to momentary faults has focused DNOs on measures to lower outage rates for customers fed from spurs. The bonus to be gained from reducing such outages is very clear, given the incentive scheme imposed by the national energy regulator. The Distribution Network Operator installed cutout mounted reclosers on 29 spurs operating at 10kV and 20kV and have monitored their operation closely for over a year now. There were some initial issues around the handling/operation of the Cutout mounted reclosers and in the selection of suitable spurs for inclusion in the trial. Since then, the cutout mounted reclosers have operated as expected and some outage penalties have been avoided. Results so far are generally positive but must be considered interim until a larger volume of feedback/monitoring information has been gathered and analysed. The ratings of the cutout mounted recloser were not ideally matched to the characteristics of the trial network, so opportunities for improvement remain.