Siemens SIRIUS 3RU2116-1FB0 Thermal Overload Relay, 1.1-1.6 A, Class 10, S00, Contactor Mounting

In industrial control panels, a motor draws current beyond its rated capacity due to a mechanical jam; the Siemens 3RU2116-1FB0 thermal overload relay senses the excess heat and trips the contactor, preventing winding damage. This SIRIUS relay is a compact, three-pole protective device for motors up to 1.6 A, built for direct mounting on Siemens contactors of size S00. Its thermal release mechanism responds to overload conditions according to trip class 10, and the current setting dial is adjustable from 1.1 A to 1.6 A. The relay includes one normally open and one normally closed auxiliary contact for control signaling, and both main and auxiliary circuits use screw terminals for secure wiring. Rated for operational voltages up to 690 V AC and insulation voltage of 690 V, it withstands impulse voltages up to 6 kV. With an IP20 degree of protection, it is intended for installation in enclosed electrical cabinets. The reset function can be set to manual or automatic, offering flexibility for different operational strategies. Compliant with IEC 60947-4-1 and IEC 60947-5-1, this relay operates reliably in ambient temperatures from -20 °C to +60 °C and can be stored between -50 °C and +80 °C.

Key specifications

• Current setting range: 1.1 - 1.6 A
• Trip class: 10
• Size: S00, contactor mounting
• Number of poles: 3
• Rated operational voltage (Ue): 690 V AC
• Rated insulation voltage (Ui): 690 V
• Rated impulse withstand voltage (Uimp): 6 kV
• Degree of protection: IP20
• Main and auxiliary circuit connection: Screw terminals
• Auxiliary contacts: 1 NO + 1 NC
• Reset function: Manual/automatic
• Overload release type: Thermal
• Ambient operating temperature: -20 to +60 °C
• Ambient storage temperature: -50 to +80 °C
• Power loss: 7.2 W at rated current
• Short-circuit protection for auxiliary circuit: Fuse 6 A gG/gN
• Standards: IEC 60947-4-1, IEC 60947-5-1

Why choose it

This relay offers precise motor protection in a compact S00 footprint, making it ideal for space-constrained control panels. Its thermal overload release provides reliable tripping for motors with rated currents between 1.1 A and 1.6 A, and the adjustable setting dial allows fine-tuning to match the motor's full-load current. The manual/automatic reset option gives you control over restart behavior after a trip, enhancing operational safety. With screw terminals and direct contactor mounting, installation is straightforward and secure. Compliance with international standards ensures compatibility and performance in demanding industrial environments.

Ideal use cases

• Protecting small three-phase motors in conveyor systems, pumps, and fans
• Motor starter combinations with Siemens S00 contactors
• Control panels requiring compact, DIN-rail-friendly components
• Applications needing manual or automatic reset after overload
• Industrial machinery with frequent starting and stopping cycles

Good to know

The relay is designed for use in enclosed electrical operating areas with IP20 protection; it is not suitable for direct exposure to dust or moisture. For short-circuit protection of the auxiliary circuit, use a fuse rated 6 A gG/gN. The thermal release mechanism operates without external power, relying on the heat generated by the motor current. When mounted on a contactor, the relay's main terminals connect directly to the contactor's output, simplifying wiring. Always verify that the motor's full-load current falls within the relay's setting range to ensure proper protection.