Siemens 3RV2021-4DA10 Solid State Soft Starter

Siemens 3RV2021-4DA10 is a SIRIUS 3RV2 motor starter protector designed for DIN-rail mounting in three‑phase motor circuits. It provides overload protection with an adjustable current release (A‑release) in the 18–25 A range, enabling protection for motors around 11 kW at 400 V. The unit supports a broad operating voltage of 220–690 VAC, comes in the compact size S0 form factor with screw terminals, and is part of Siemens' 3RV2 family of motor protection devices. This device combines protection and manual switching in a single DIN-rail module, suitable for installation in control panels and automation cabinets to guard motors against overloads and to facilitate controlled start/stop sequences. Short‑circuit current ratings and exact switching characteristics are specified by Siemens in official catalogs and datasheets, ensuring compatibility with standard motor protection schemes in industrial environments.