Intended to compensate for the capacitive line-to-earth current during a 1-phase earth fault. The Arc Suppression Coils represents the central element of the Trench earth-fault protection system that features: Up to power ratings of 35 MVAr, Up to system voltage of 145 kV, Current regulation range 10 - 100 % and a available Various design alternatives. Based on extensive experience in design, construction and application of ASCs, Trench products can meet the most stringent requirement for earth-fault compensating techniques. By continuously utilizing variable arc suppression coils, ideal compensation of the earthfault current, it can achieve the optimal efficiency of the resonant earthing technique and in order to eliminate earthfaults rapidly, the faulty feeder has to be detected quickly and selectively.