What this SIRIUS reversing load feeder packs
The Siemens 3RA1220-1DB24-0AP0 is a non-fused reversing load feeder from the SIRIUS family, size S0. It's a reversing starter assembly — meaning it combines a contactor pair, a bimetal overload relay, and a circuit-breaker in one DIN-rail-mounted block. Rated 1.1 kW at 400 V, it handles reversing motor loads like conveyors, hoists, and gate drives where direction change is part of the cycle. The supplied circuit-breaker is a 3RV10 21-1DA10, and the supplied contactor is a 3RT10 24-1AP00 — both matched to the S0 frame. That means the short-circuit protection and switching duty are coordinated out of the box, no separate sizing exercise.
Mounting and wiring — what fits where
Snaps onto 35 mm standard rail (EN 60715). Horizontal mounting position only. Dimensions: 100 mm wide, 220 mm tall, 119 mm deep. Clearance requirements: 30 mm upward, 10 mm forward, 9 mm backward, 0 mm downward, 30 mm at the side. That forward clearance is tight — plan for gland plates or busbar covers that might eat into it. Wire range: solid or stranded 1 to 6 mm² on the main contacts, with dual-wire capability: 2x (1 to 2.5 mm²) or 2x (2.5 to 6 mm²). AWG equivalent for main contacts is 2x (14 to 10). That covers most motor branch circuits up to the 1.1 kW rating.
Shock resistance 12.5g. No PROFINET or PROFIBUS DP onboard — this is a pure power device, no fieldbus.