Siemens 3RU2116-0KB0 Thermal Overload Relay

Siemens 3RU2116-0KB0 is a SIRIUS 3RU2 thermal overload relay designed to protect three‑phase motors by sensing current in the main circuit and tripping when overload conditions occur. Sized for S00‑size contactors, it mounts directly on the main circuit and uses screw terminals for both the main and auxiliary/control wiring, with a built‑in manual or automatic reset option. The relay covers a preset current range of 0.90 to 1.25 A and is classified for Class 10 protection, delivering reliable motor safeguarding for small to mid‑sized loads. It features a nominal insulation voltage of up to 690 V and front IP20 protection, suitable for standard industrial enclosures. Operational environmental limits are -40 to +70 C, with storage and transport ranges of -55 to +80 C, and it supports installation up to 2,000 m above sea level. Typical power loss is 4.8 W, and the device is rated to withstand impulse voltages up to 6 kV and mechanical shocks of 8 g / 11 ms. This 3‑pole overload relay is designed for stand‑alone installation and is part of Siemens’ SIRIUS 3RU2 motor protection family, providing precise current‑based protection in control panels and motor starter assemblies.