The Siemens 3RA2125-1FD24-0AK6 is a non-fused direct motor starter from the SIRIUS family, combining a contactor and a thermal bimetallic overload relay in a single S0-size package.
Panel fit and mounting constraints
The starter snaps onto 60 mm busbar systems (fastening method per) and must be mounted vertically. Dimensions are 45 mm wide × 260 mm high × 155 mm deep — the width is the critical panel pitch dimension for multi-feeder layouts. Required clearances: 30 mm upward, 10 mm forward, 10 mm downward, 9 mm at the side, and 0 mm backward — the backward clearance of zero means the unit can be placed flush against the back panel, simplifying enclosure depth planning. Main contact wire range accepts 1 to 10 mm² stranded, or two conductors of 2.5 to 6 mm² each — useful for looping through multiple starters on a common bus.
Lifecycle and compliance documentation
The integrated contactor is a 3RT2024-1AK60 and the link module is a 3RA2921-1AA00 — these are the service-replacement sub-assemblies if the unit fails in the field.