What it is and what it does
The Siemens 3RT2346-1AK60 is a 4-pole power contactor from the SIRIUS series, sized S3. Its AC-1 rating of 140 A at 400 V / 40 °C means it handles resistive heating and lighting loads up to that current without derating — the rating that governs continuous duty in panel builds. The coil is wound for 110 V AC at 50 Hz or 120 V AC at 60 Hz, so a single part covers both line frequencies common in North American and European panels. The screw terminals on the S3 frame accept standard lug or ring terminations, and the built-in auxiliary contact block (1 NO + 1 NC) gives you one feedback signal for the PLC and one for a status lamp or interlock without adding a side-mount module.
Sourcing and lifecycle
RoHS compliance is confirmed since 01-09-17, and REACH Article 33 candidate-list information is available on request. Export control is AL N / ECCN EAR99, so no special licensing for cross-border shipments.
Panel integration notes
The S3 frame footprint (146 x 136 x 177 mm packaged) mounts on standard DIN rail or panel plate. The 4-pole configuration means it occupies the width of a standard S3 contactor — about 55 mm on the rail — leaving room alongside for overload relays or busbar systems. The 110 V AC coil draws inrush current at pickup; verify your control transformer is sized for the magnetizing surge if multiple contactors pull in simultaneously.
What the AC-1 rating means for selection
AC-1 is the resistive load category — heaters, incandescent lighting, resistive banks. The 140 A figure is the thermal continuous current at 40 °C ambient. If your load is motor (AC-3) or mixed, you need the motor-rated version (3RT2... with a different coil code) because the AC-3 breaking current is lower for the same frame. This part is for resistive switching, not motor starting.