The ABB 1SNA645529R0000 is a solid state, 1-phase relay. It features an electronic current sensing switch, with a load current rating of up to 20A. The relay is designed for use in 1-phase AC circuits and provides protection against overloads, misuse, and short-circuits. With an operating voltage range of 24-240VAC, this device makes a great choice for a variety of applications. Additionally, the 1SNA645529R0000 has a wide temperature range (-25 to +85 degrees Celsius) as well as several features designed to ensure reliable operation, such as EMC compliant Snubber, surge resistance and a contact wipe mechanism.