Siemens 3RT2018-1BB42 Three-Phase Industrial Contactor

Siemens 3RT2018-1BB42 is a compact three-pole power contactor designed for AC-3e/AC-3 duty and intended to start and stop three‑phase motors. It uses a 24 V DC coil to energize three normally open main contacts (3NO) and includes one normally closed auxiliary contact (1 NC) for signaling or interlock purposes. Rated for 16 A in AC-3 service and capable of switching up to 7.5 kW at 400 V, this size S00 device features screw-terminal connections for reliable panel wiring. The unit’s small footprint makes it suitable for crowded control cabinets, while its Siemens Sirius family pedigree ensures compatibility with other 3RT components and standard auxiliaries. Typical applications include controlling fans, pumps, conveyors, or other motor-driven loads in automation systems, with the auxiliary contact available for PLC input or interlocking logic. When integrating this contactor, verify that the motor’s starting current remains within the 16 A rating and that the 24 VDC control circuit is supplied by a compatible controller, ensuring proper de-energization and safe operation in your control scheme.