The Siemens 3RU6116-1GB0 is a SIRIUS thermal overload relay sized for motor protection in the 4.5 to 6.3 A adjustable range, Trip Class 10. It mounts directly onto a Size S00 contactor, which is the compact frame for small motor starters up to around 3 kW at 400 V. The relay uses a bimetallic thermal element — no electronics to drift — and the trip curve is calibrated to IEC 60947-4-1.
The adjustable current range of 4.5 to 6.3 A sets the full-load motor current it protects. Set the dial to the motor nameplate FLA. If the motor drives a high-inertia load (centrifuge, large flywheel) that needs a longer start, Class 10 may trip during acceleration; that application calls for Class 20 or 30. The 6 kV rated surge voltage aligns with IEC 60947-1 overvoltage category III for industrial panels. The 50/60 Hz operating frequency is standard for mains-fed motor circuits worldwide. In a dense panel with multiple relays side by side, that heat adds up. The relay is rated for ambient operation from -40 to +70 °C, so derating for elevated cabinet temperature is not needed within that range, but the 5.7 W per unit still contributes to the enclosure's thermal budget.
Fastening method is contactor mounting — the relay clips directly onto the S00 contactor, no DIN rail required. Main circuit terminals are screw-type, top and bottom, accepting 2×(0.5…1.5 mm²) solid/stranded or 2×(0.75…2.5 mm²). Tightening torque is 0.8 to 1.2 N·m. Auxiliary circuit terminals are also screw-type, accepting 2×(20…16) AWG. The manual/auto reset selection is a switch on the front — auto reset for remote panels, manual for local restart after a trip.
The relay carries a substance prohibitance date of 05/01/2012, which aligns with RoHS compliance effective from that date. The product is designed to IEC 60947-4-1 for motor starters. The shock resistance rating of 8g / 11 ms per IEC 60068-2-27 confirms suitability for industrial environments with vibration. Operating humidity range is 0 to 90%. Installation altitude is limited to 2,000 m above sea level without derating.