Explore top companies in protective relay market, market share, leading players, and strategic insights shaping grid protection and smart energy systems by 2034. NOARK Electric North America, 2. 5 billion by 2034, expanding at a CAGR of approximately 6. These relays are designed to keep an eye on. SEL relays detect faults and other abnormal conditions in electric power systems and initiate protective actions to maintain system stability and safety. Not finding the product that you're looking for? View legacy bus protection products. Key Relay Products: General Purpose Relays, Timer Relays, Monitoring Relays, Power Relays.