Siemens 3UA50-00-0K Relay

Siemens 3UA50-00-0K overload relay delivers thermal-delay protection for World Series motor starters, with a fixed setting range of 0.8 to 1.25 A to match standard motor control needs. Rated for up to 690 V, it protects motors in AC circuits by tripping when the current exceeds the setpoint.

The unit provides 1 normally open (NO) and 1 normally closed (NC) auxiliary contact, a manual reset button, and is supplied with wiring connectors and terminals for straightforward installation and wiring in Siemens control panels and starter assemblies.

Designed to pair with Siemens World Series contactors, it is compatible with commonly paired models such as 3TF30, 3TF31, 3TF40, 3TF41, and 3TB40/3TB41, enabling seamless replacement or upgrade within existing motor control circuits.

As an OEM-compatible component, the 3UA50-00-0K can serve as a direct substitute in replacement scenarios, offering reliable overload protection for 0–690 V AC motor systems. Typical weight is about 0.44 lb, reflecting a compact module suitable for integration into compact control cabinets.