Shunt reactors are compensation components used to balance capacitive loads by creating an inductive effect when engaged by a reactive power control relay as capacitive load increases. The capacitive effect caused by long underground power lines, UPS units, computers, electronic ballasts, and LED lighting is compensated and balanced through the use of shunt reactors.

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