It protects a 3-phase motor by monitoring current through its three main poles and tripping on a sustained overload according to a Class 10 curve — meaning it must trip within 10 seconds at 7.2× the set current, a standard for standard-duty induction motors starting under load. The adjustable current response range is 2.2 to 3.2 A, set via a dial on the front. This covers small motors in the 0.75–1.5 kW range on 400 V supplies. The relay is thermal, bimetallic strip design — no electronics to fail, but it does need a cool-down period after a trip before it resets.
Where it fits — panel and contactor integration
This is a size S00 relay, meaning it is designed to mount directly below a S00-frame contactor like the 3RT201 or 3RT101 series. The connection arrangement places main circuit terminals top and bottom, so the contactor output feeds straight into the relay input with no extra wiring. Dimensions are 45 mm wide, 89 mm tall, and 80 mm deep. Side spacing to grounded parts must be at least 6 mm. The tightening torque for the main screw terminals is 0.8 to 1.2 N·m.
Rated operational current is 3.2 A at 690 V, 50/60 Hz. The insulation voltage is 690 V with pollution degree 3, and surge voltage resistance is 6 kV — this is the standard coordination level for industrial control panels. The relay can be installed up to 2000 m above sea level without derating. Power dissipation is modest: 5.2 W typical total, 5.7 W at rated current in hot operating state, and 1.9 W per pole. This keeps the heat rise low inside a sealed enclosure. Humidity tolerance is 0 to 90% relative humidity during operation. The auxiliary and control circuits use screw terminals as well, accepting 2× (0.5 to 1.5 mm²) solid or 2× (0.75 to 2.5 mm²) stranded. AWG equivalents are 2× (20 to 16) for main contacts and 2× (20 to 16) or 2× (18 to 14) for auxiliary contacts. Shock resistance is 8g for 11 ms per IEC 60068-2-27.
Compliance documentation is standard for Siemens industrial controls: RoHS compliance date is May 1, 2012 (substance prohibitance date). The relay carries the usual CE, UL, CSA, and IEC certifications for the SIRIUS family, though specific approval marks are not listed in this record. The product designation is clear from the nameplate: SIRIUS 3RU6116-1DB1, thermal overload relay, 2.2-3.2 A, Class 10.