Our relay protection tester offers comprehensive testing for both optical digital and traditional protective devices. It's ideal for power plants, substations, equipment manufacturers, and institutions needing relay protection evaluations. Does Megger have products and tools for IEC 61850 applications? The company released its first products for IEC 61850. Power System protection is crucial part of power station and substations safety which use protection relays and circuit breakers to isolate faulty parts or zones within the plant including Generator zone, Motor zone, Feeder zone, Bus zone, Transformer zone and Transmission Lines zone.