Siemens 3RU1146-4JB0 Industrial Power Relay Module

Siemens 3RU1146-4JB0 is a Sirius thermal overload relay, size S3, rated for 45–63 A and designed to mount on compatible contactors to protect motors from overcurrent. The unit includes 1 normally open and 1 normally closed auxiliary contact for signaling and control integration, and it carries a class 10 trip rating. Key electrical specs include IP20 front protection, insulation voltage up to 1,000 V, and a typical active power loss of 16.5 W under normal operation. Operating ambient temperature range is -20 to +70 °C (storage -55 to +80 °C), making it suitable for a variety of industrial environments. Part of the Sirius family, it is intended for mounting on a compatible Siemens contactor as part of motor protection arrangements.