A low voltage relay is an electrically operated switch that uses a small control voltage (typically below 1000V AC or DC) to switch larger electrical loads on and off. These relays act as intermediaries between control circuits and power circuits, providing isolation, control, and protection. Why SIPROTEC 7SY82? SIPROTEC 7SY82 is a universal protection device for nearly all low power. Previous experience in designing low voltage and medium voltage switchgear, relay panels and custom control panels as an Electrical Engineer at ESSMetron, Denver CO. Graduated with a Master of Science in Electrical Engineering from The University of Texas at Dallas in 2018 and with a Bachelor of. SEL relays detect faults and other abnormal conditions in electric power systems and initiate protective actions to maintain system stability and safety.