The multifunctional grid protection relay is designed to monitor voltage and frequency in single- and three-phase mains. It operates on 2-wire, 3-wire, or 4-wire AC systems. The relay is based on ANSI codes including 59, 27, 81H, 81L, 78, and 81R. It has a measuring range of L-L: 0-550 VAC and L-N: 0-317 VAC.