What It Is and What It Does
The Siemens 3RT2018-2UB41 is a SIRIUS power contactor in size S00, designed for switching loads in control panels. It carries a 24 V DC coil and uses spring-type terminals for wiring. The contactor includes an auxiliary switch and is rated for 10 A at 24 V DC.
Key Ratings and What They Mean for Fit
The 24 V DC coil is the control voltage you need to supply from your PLC or relay output. The 10 A rating at 24 V DC tells you the maximum current the main contacts can switch under DC resistive load at that voltage — useful for smaller DC motor brakes or solenoid valves. For AC motor duty, the contactor's switching frequency varies by load type: up to 1000 operations per hour at AC-1 (resistive), 750/h at AC-3 (standard motor start/run), and 250/h at AC-4 (plugging/inching). The AC-3e rating also sits at 750/h, matching the standard motor duty cycle.
Mounting and Integration
Mounts via screw or snap-on onto a 35 mm DIN rail per DIN EN 60715. The size S00 footprint is compact: 45 mm wide, 70 mm tall, 73 mm deep. Clearance requirements: 10 mm upwards, downwards, and forwards; 6 mm at the side. The mounting position is flexible — +/-180° rotation on a vertical surface, and can be tilted forward/backward by +/-22.5°. Wire range: solid or stranded 0.5...4 mm², or 2x (0.5...4 mm²) for paralleled conductors. Operating temperature -25...+60 °C; storage -55...+80 °C.