Size S00 frame — what the 20-12 A main contact rating means
The 3RT2018-2KG42-0LA0: At 24 VDC the contactor switches 10 A; at 125 VDC it handles 0.9 A. This DC switching table defines the inductive load envelope — the arc extinction in DC is harder than AC, so the rated current drops as voltage rises. For a 24 VDC solenoid or valve bank, the 10 A rating gives comfortable margin.
Spring terminals and mounting flexibility
The magnet coil uses spring-type terminals — push-in connection for solid or ferruled stranded wire, no screw tightening needed.
Built-in auxiliary switch — no add-on block needed for basic feedback
An auxiliary switch is integrated into the contactor, so a separate side-mount block is not required for basic NO/NC feedback to a PLC or status lamp. This saves one DIN rail position and reduces wiring compared to a base contactor without aux contacts.