ABB 1SNA645071R0000 Interface Relay Assembly

ABB 1SNA645071R0000 is the RB121-24VDC interface relay (Form C/SPDT) used to connect low-voltage control logic to higher-power circuits in automation panels. With a 24 V DC coil, it energizes to switch a single Form C contact rated for up to 6 A at 250 VAC, enabling reliable isolation between PLC outputs and AC loads. The unit uses screw-terminal wiring and is designed for DIN-mount installation within ABB’s RB121 family (R600 series) of interface relays, offering compact, plug-compatible replacement within ABB control architectures. Typical applications include PLC-to-AC load interfacing, signaling and interlock circuits, and general-purpose control tasks where an SPDT contact is required to route a signal or drive a secondary relay or contactor. The 1SNA645071R0000 code specifies a 24 V DC coil RB121-24VDC relay, making it suitable for ABB automation systems that rely on the RB121 family for modular, field-installable interface solutions.