Siemens SIRIUS 3RU2 Thermal Overload Relay 1NO + 1NC, 14 → 20 A F.L.C, 20 A Contact Rating, 7.5 kW, 3P, SIRIUS

Switch position indicator and test function
STOP button
Selector switch for manual/automatic reset
Screw connection or Spring-clamp versions
Impulse voltage resistance 6 kV
Insulation voltage 690V
Surface or DIN-rail stand-alone mounts available, see 706-1699 etc

The 3RU21 thermal overload relays up to 80 A have been designed for current-sensitive protection of loads with normal starting.
These thermal overload relays for use with Sirius Size S0 & S00 Contactors

Screw terminals can only be used with screw terminal overloads and spring terminals can only be used with spring terminal overloads.

CE, UL, CSA

This thermal overload relay plays a vital role in protecting electrical motors, specifically designed for those operating within a current range of 14 to 20 A. Featuring both automatic and manual reset functions, it helps prevent damage caused by overload situations. Its durable design allows for easy installation directly onto contactors, making it suitable for various automation and electrical machinery applications.

• Provides continuous protection for 3-phase motors
• Automatic reset feature enhances operational convenience
• Integrated auxiliary contacts for additional functionality
• Compact dimensions support space-efficient installations

• Applicable with industrial machinery to ensure operational safety
• Can be integrated into commercial electrical systems
• Commonly used in manufacturing environments for motor protection

The device can be installed directly on contactors using screw terminals, ensuring a straightforward setup.

Upon a fault occurrence, the device disconnects the motor and automatically reconnects once the fault is resolved.

Yes, it is rated for safe operation with currents up to 20A.

Yes, it performs well within a temperature range of -40 to +70°C.

Siemens Sirius Range Contactor & Control Relays