Integrator's note on the 3RT1034-3KF44-0LA0
The Siemens SIRIUS 3RT1034-3KF44-0LA0 is a S2 frame power contactor rated for motor switching at 18.5 kW on 500 V AC-3 duty, or 10 kW at 690 V AC-3. Coil is 110 V DC, which means you need a separate DC supply or a rectifier module in the panel; verify your control transformer and rectifier sizing before wiring.
RoHS compliance date is noted as May 1, 2012, so the design predates the more recent substance restrictions but meets the original RoHS directive. If your compliance team needs a Declaration of Conformity or REACH documentation, that's standard Siemens paperwork available through the supply chain.
Termination and wiring details
Main circuit terminals accept 2x (0.75...25 mm²) stranded or 2x (0.25...2.5 mm²) solid wire. At 40 °C, the minimum permissible cross-section is 16 mm² for the main conductors — that's the thermal limit for full rated current, not a mechanical minimum. Side-by-side mounting is allowed with no derating penalty, which saves panel width when stacking multiple contactors.