What this control unit does in the starter assembly
The 3RW4758-6SC44 is a control unit — the logic board that triggers the SCRs in the 3RW4458 soft starter. It runs on 230 V control supply and terminates through screw terminals, so you land the control wiring directly without a separate connector kit.
Voltage match and terminal style — the fit check
Screw terminals mean you can land solid or stranded wire with a standard slotted driver. No push-in or spring-clamp tool needed, which is handy for retrofit swaps where the existing wiring is already stripped for screw clamps.
Compliance documentation on record
The substance prohibitance date is 05/01/2012, which aligns with RoHS compliance — the control unit meets the EU restriction on hazardous substances effective from that date. REACH and UL documentation would be part of the Siemens standard declaration package; confirm with the supplier if a specific certificate is needed for your QA gate.