SIRIUS S00 power contactor with 48 VDC coil
The Siemens 3RT1017-2BW42 is a SIRIUS S00 power contactor with a 48 VDC coil, spring-loaded terminals for the main circuit, and a screw and snap-on mount onto 35 mm DIN rail per EN 50022. It's rated for motor switching up to 5.5 kW at 400 V and 690 V in AC-3 duty, and handles 8.5 A in AC-4 for reversing or plugging applications. The DC coil pulls 3.3 W to close and holds at the same power, so no extra hold-in economizer is needed — just watch the polarity on the free-wheel diode if you're wiring inductive loads downstream.
The 48 VDC coil isn't just about pull-in voltage; the contactor's auxiliary switching capacity at DC matters when you're breaking inductive loads on the same panel. At 24 V it switches 10 A, at 60 V it drops to 2 A, at 110 V it handles 1 A, and at 220 V it's down to 0.3 A. Those numbers follow the DC arc extinction curve — the higher the voltage, the harder it is to snuff the arc in air. If you're switching a 48 VDC solenoid bank, stay under 2 A per contact or use a suppressor.
Panel integration — DIN rail, spring terminals, and spacing
The S00 frame is 45 mm wide, 60 mm tall, and 73 mm deep — a compact footprint that fits standard 35 mm DIN rail. Spring-loaded terminals accept 2x (0.25 to 2.5 mm²) solid or stranded, or 2x (24 to 14 AWG).