What it is and what it does
The Siemens 3RK1903-3AE10 is a TM-PFX30 S47-G0 potential group distributor in the SIRIUS family, designed for infeed from the left and forwarding U1 m SG1 to six external ET200S stations at 30 mm width. This part distributes the potential group supply from a single infeed point to multiple ET200S remote I/O stations.
Where it fits in the panel
The 30 mm width matches the standard ET200S module footprint on a 35 mm DIN rail per EN 50022, and the left-side infeed orientation means it occupies the first slot in the potential group — plan the rail layout so the feed terminals are accessible for the incoming 24 V DC supply cable. Because the part forwards the potential to up to six downstream ET200S stations, the total current draw of those six stations' loads must stay within the rating of the upstream power supply and the infeed terminals on this distributor — no built-in fuse, so the branch protection is external.
Lifecycle and compliance
Substance prohibitance date is 05/01/2012.