Siemens Overload relay, 2.8 - 4A thermal for motor protection, size S00 Part number 3RU2116-1EB1

Product Overview

The Siemens 3RU2116-1EB1 is a thermal overload relay from the SIRIUS 3RU2 family (size S00), designed to protect three-phase motors from overload, phase failure or prolonged overcurrent. It provides adjustable overload protection (2.8 … 4.0 A) and includes auxiliary contacts for signalling or control circuits. The device may be used as a stand-alone overload protection unit or mounted directly to compatible contactors for compact motor starter assemblies.

Key Features

• Thermal overload relay, SIRIUS 3RU2 series, size S00
• Adjustable overload protection: 2.8 – 4.0 A (trip class 10)
• Three-pole main circuit suitable for 3-phase motors
• Auxiliary contacts: 1 NO + 1 NC — for signalling or control integration
• Manual or automatic reset option — allows flexibility in operation after trip
• Screw-terminal connections for main and auxiliary circuits — reliable for industrial wiring
• Rated insulation voltage up to 690 V, surge withstand up to 6 kV — suitable for industrial supply environments
• Ambient operating temperature: –40 °C … +70 °C — wide environmental tolerance
• Compact S00 size — suitable for mounting on small contactors or in constrained control compartments

Technical Specifications

• Article Number: 3RU2116-1EB1
• Product Type: Thermal overload relay, SIRIUS 3RU2 series
• Contactor Size (compatible): S00
• Overload Adjustment Range: 2.8 … 4.0 A
• Number of Poles (Main Circuit): 3-pole (for 3-phase motors)
• Auxiliary Contacts: 1 NO + 1 NC (for signalling / control output)
• Reset Type: Manual or automatic reset selectable
• Rated Insulation Voltage (Ui): 690 V
• Surge Withstand Voltage: 6 kV
• Protection Class / Housing Rating: IP20 (when terminals and housing correctly enclosed)
• Ambient Operating Temperature: –40 °C … +70 °C
• Pollution Degree / Environmental Rating: Pollution degree 3 (industrial environments)
• Mounting / Connection: Screw terminals for main and auxiliary circuits; direct mounting on compatible size-S00 contactors or stand-alone installation
• Reset / Trip Indication: Overload trip with thermal-bimetal mechanism; auxiliary contacts change state on trip for external signalling or control logic

Compliance & Standards

• Part of Siemens SIRIUS 3RU2 motor-protection relay family — designed for IEC/EN conformity in motor protection circuits
• Insulation and surge withstand ratings suitable for industrial AC motor supply (up to 690 V)
• Suitable for ambient and environmental conditions common in industrial control panels and motor starter systems

Applications

The 3RU2116-1EB1 is ideal for protecting three-phase motors against overload, phase imbalance, and prolonged overcurrent — commonly used in small motor feeders, compact motor starters, pumps, fans, compressors, HVAC systems, and light- to medium-duty machinery. It works as part of a complete motor starter (in combination with contactors), or as a stand-alone overload relay for retrofit or custom control-panel installations requiring adjustable protection and external signalling integration.