Siemens SIRIUS 3RT2018-2KF42-0LA0 — DC Coil Contactor, Size S00
The Siemens 3RT2018-2KF42-0LA0 is a SIRIUS contactor in size S00, built for DC coil control at 110 V. It uses spring-type terminals for the magnet coil — no screw torque to verify, just strip and push. Rated for 10 A at 24 V DC and 14 A at 480 V DC, it handles DC loads across a wide voltage range. The contactor mounts via screw or snap-on onto a 35 mm DIN rail per DIN EN 60715, fitting into standard panel layouts with a 45 mm width and 121 mm depth.
DC Switching Ratings and Coil Performance
This contactor is optimized for DC circuits. The coil picks up at 70% of rated voltage (77 V for a 110 V coil) and drops out at 1.25x the rated value — meaning it holds in firmly until the control voltage drops significantly. Arcing time runs 10–15 ms for the main contacts, with a DC arcing time of 7–20 ms depending on the load. Mechanical life is rated at 30 million operations, so it suits high-cycle applications like conveyor indexing or valve actuation.
Wiring and Terminal Capacity
The spring-type terminals accept solid wire: 2x (0.5–1.5 mm²), 2x (0.75–2.5 mm²), or 2x 4 mm². For solid or stranded wire, the range is 2x (0.5–4 mm²). That covers most control and power wiring in a panel — no special ferrules needed unless your standard calls for them. The auxiliary switch is built in, so you don't need a separate add-on for feedback or status.
Mounting and Environmental Specs
Mounting position is flexible: the contactor can be rotated ±180° on a vertical surface and tilted forward/backward ±22.5°. Clearance requirements are minimal — 10 mm upwards, 10 mm forwards, 10 mm downwards, and 6 mm at the side. Operating temperature range is -40 to +70 °C, with storage from -55 to +80 °C. That covers most indoor industrial environments, including unheated warehouses.