Shunt reactors are compensation elements used in compensation systems to balance capacitive loads. They are activated by a reactive power control relay when the capacitive load increases, thereby creating an inductive effect. The capacitive effect caused by long underground power lines, UPSs, computers, electronic ballasts, and LED lighting is compensated and balanced by the use of shunt reactors.

Sigma Shunt Reactors are manufactured in single-phase stages from 0.25 kVAr to 10 kVAr and in three-phase stages from 0.25 kVAr to 50 kVAr.