AS-i Compact Starter for Distributed Motor Control
The Siemens 3RK1322-0BS12-0AA0 is a SIRIUS AS-i compact starter — a direct-on-line (DOL) motor starter with solid-state switching and solid-state motor protection, housed in an IP65 enclosure for distributed installation right at the motor. It's designed for the AS-interface bus network, with two integrated inputs for local sensors and a 9-pole power connection via tab terminals. Rated for 2.2 kW at AC-3 duty on a 400 V supply, the setting range covers 2 A to 5.95 A — so it handles standard 0.75 kW to 2.2 kW three-phase motors. The solid-state motor protection eliminates nuisance thermal overload trips common with bimetal relays in high-cycle applications. The IP65 rating means the entire starter — electronics, power connections, and bus interface — withstands washdown and dust ingress. Mount it directly on the machine frame or conveyor structure, not back in the panel. That saves cabinet space and shortens motor power cabling.
Breaking Capacity and Short-Circuit Coordination
The 100 kA short-circuit breaking capacity (Icu) at 400 V is the standout spec for anyone doing selectivity studies. For a distributed starter mounted at the motor, this means you can size the upstream feeder breaker for the cable rating, not the fault current — the starter handles the full 100 kA itself. Short-circuit protection is fuse-based (design of short-circuit protection: fuse). The solid-state switching contacts don't weld like conventional contactors, so the fuse is the only sacrificial element in a fault event. That keeps replacement costs low — swap the fuse, not the starter.
AS-Interface Integration and I/O
This starter communicates via AS-interface protocol — not PROFIBUS DP. That's a key distinction: AS-i is a bit-level fieldbus for simple sensors and actuators, running on a two-wire flat cable that also carries 24 V DC power. The starter's two integrated inputs let you wire local limit switches or proximity sensors directly into the unit, reducing junction box complexity. The DC voltage type (24 V nominal from the AS-i bus) powers the electronics and the solid-state switching. No separate control voltage needed — the bus cable is the power source. The equipment marking per DIN EN 61346-2 is Q, confirming it's classified as a motor starter in the schematic.
Dimensions: 190 mm deep, 120 mm wide, 270 mm tall. That's a compact footprint for a fully self-contained starter with bus interface and integrated inputs. No brake output on this variant (product component motor brake output: No), so if you need a motor brake, this isn't the version — look for the -0BS12-0AA0 suffix with brake contact.