The Siemens 3RU1146-4JB0 is a SIRIUS thermal overload relay designed for reliable and precise motor protection. It safeguards motors against thermal overload and phase failures by accurately monitoring the motor current. This device is part of the SIRIUS modular system and is engineered for direct mounting onto a contactor, creating a compact and efficient motor starter assembly. With an adjustable current setting and a robust design, this overload relay is ideal for use in various industrial applications, ensuring the longevity and operational safety of critical motor-driven equipment.