How to size The DOL Motor Starter knowing that the motor is a part winding start motor
Motor Part Winding starting schemes result in a 60-40 split, so the Start winding is 60% of the current, the Run winding adds the other 40%. Those numbers actually track the values on the nameplate.
When you size contactors, you size them based on the Full Load Amps, in this case the &quot;Betr. strom&quot; of 43.9A; the starting current surge is assumed in any motor contactor design rating.
So you could (in theory) use a contactor rated for 28A on the Start and 17.6 for Run. But most people just get a pair of matching contactors for PW starting. So if you used a pair of contactors rated for 15kW 400V motors AC-3, you are good to go.