What this SIRIUS direct starter packs
The 3RA2115-1FD15-1AK6 is a Siemens SIRIUS non-fused direct starter, size S00, combining a 3RT2015-1AK61 contactor and a thermal bimetallic overload relay in one factory-matched assembly. The Class 10 trip curve means it protects standard squirrel-cage motors during start-up — it lets the motor pull locked-rotor current for up to 10 seconds at cold start before the bimetals bend enough to trip. At 460/480 V it's rated 3 hp, and at 575/600 V also 3 hp, with the full-load current at 480 V being 4.8 A and at 600 V being 4.55 A.
Mounting and panel fit
Snaps directly onto 60 mm busbar systems — no DIN rail adapter needed for that busbar pitch. Mounting position is vertical only, with 20 mm clearance upwards, 10 mm downwards, and 9 mm at the sides. The 45 mm width per starter means you can pack multiple units side-by-side on the busbar, but the vertical-only restriction and the 155.1 mm depth matter when laying out the enclosure depth.
It ships as a complete sub-assembly: the contactor and link module (3RA1921-1DA00) are supplied together, so you're not piecing together a contactor and overload from different bins.