27kV or 38kV? Voltage class and insulation level selection decision tree for high-voltage AC automatic reclosers
Instantaneous faults on overhead lines account for the majority of trips; the value of a recloser lies in turning detection, tripping, and reclosing into a closed loop, reducing the outage time spent waiting for manual closing. The core of selection is not that a higher voltage class is always better, but rather matching the recloser's rated voltage, the system's highest voltage and insulation level, and altitude and pollution corrections as three aligned factors. The following breaks down, according to a four-step decision tree, how the 15 kV, 27 kV, and 38 kV tiers are implemented, and provides a checklist of line and SCADA materials that must be prepared before procurement.