The Siemens SIRIUS 3RT1916-2FK11 is a clip-on auxiliary switch rated for a maximum of 3 A, designed to snap onto SIRIUS contactors and add signal feedback or control logic to a motor starter assembly. The contact ratings are voltage-dependent: 1 A at 24 V, 0.2 A at 125 V, and 0.1 A at 250 V — so the 3 A maximum only applies at lower voltages; at typical control voltages (120 VAC) the actual switching capacity is lower. Coil pickup is 100–127 V at 50/60 Hz, with a dropout threshold around 85 % of rated voltage (0.85 initial value), and a recovery time of 150 ms before the coil can re-energize after drop-out.
Mounting and integration
Clip-on fastening means it snaps directly onto the front or side of a SIRIUS contactor without tools — no DIN rail footprint consumed, but it does add 45 mm width and 75 mm depth to the contactor envelope. Accept stranded or solid wire from 18 to 14 AWG; mounting position is unrestricted, and the operating temperature range of -25 to +60 °C covers most panel environments. Pollution degree 3 (conductive pollution or dry non-conductive pollution that becomes conductive due to condensation) and basic insulation — typical for industrial control panels not hermetically sealed.