SIRIUS S3 contactor — AC coil, DIN-rail fit
The Siemens 3RT2344-1AP60 is a size S3 SIRIUS contactor with an AC magnet coil rated 220 V at 50 Hz and 240 V at 60 Hz. The 10 million typical mechanical cycle rating sets a service-life baseline for the contactor's switching mechanism — in a 1-cycle-per-minute application that translates to roughly 19 years before mechanical wear-out, though coil and contact life under load will be the actual limit.
Main and auxiliary circuit wiring
Main circuit power connections accept stranded wire from 6 mm² up to 70 mm² — sufficient for motor loads up to the contactor's rated current. These ratings cover most PLC input and relay coil loads found in industrial panels.
Environmental limits and storage conditions
The AC coil uses screw-type terminals — field-serviceable without special tools. Coil power factor is 0.35 at 50 Hz and 0.41 at 60 Hz, which influences the VA burden on the control transformer.
Switching timing and coordination
Arcing time is 10 to 20 ms, and AC switching time is 10 to 21 ms. These timing windows matter when coordinating with PLC scan cycles or safety relay response times — a fast-scanning PLC may need input filtering to avoid seeing the arcing transient as a false signal.