The Siemens 3RT2016-2HB42 is a SIRIUS coupling contactor in Size S00, designed for switching loads where the control circuit needs isolation from the power circuit — typical in panel interlocking, signal isolation, or as a slave contactor driven by a PLC output. The 24 VDC coil pulls in at 0.7 of rated voltage and holds across the full -25 to +60 °C operating range, so it's reliable on a standard 24 V control supply even in a warm cabinet. Rated operational current is 10 A at 24 V, with derated values at higher voltages — 3 A at 400 V, 1 hp at 230 V — so it handles small motor loads, resistive heaters, or signal-level switching in control circuits.
That saves time on repetitive wiring in panel builds.
Actual electrical life depends on the duty class: AC-1 (resistive) allows 1,000 operations per hour, AC-3 (motor starting) and AC-3e (enhanced motor) allow 750 per hour, while AC-4 (plugging/reversing) drops to 250 per hour.