The Siemens 3RW5951-0PB05 is a replacement PCB for the 3RW55 soft starter family, sized for the Size 1 frame and rated for 18 A continuous current at 600 V. It belongs to the spare parts group for 3RW55 soft starters, meaning it is the control/power board that sits inside the starter enclosure — not a standalone soft starter itself. If you are servicing a 3RW55 Size 1 unit and the PCB has failed, this is the factory-specified replacement board.
Compliance and physical fit
RoHS compliant since 15 February 2018, with a REACH Article 33 disclosure for lead (CAS 7439-92-1) above 0.1% w/w — a standard declaration for electronic assemblies containing leaded solder. The packaging dimensions are 398 x 192 x 78 mm, which matches the envelope of the 3RW55 Size 1 chassis.