Integrator's terse spec recap — what this SIMATIC motor starter is
The Siemens 3RK1301-0AB20-0AA3 is a SIMATIC direct motor starter — a single unit combining contactor, overload relay, and communication interface for a standard induction motor start. It handles a 24 V DC control supply (20.4 to 28.8 V DC permissible) and is rated for direct-on-line starting only; no reversing capability built in. That rating is per IEC 60947-4-1, the standard for motor starters and contactors. The adjustable trip class (CLASS 10 and 10A) lets you match the overload curve to the motor's thermal withstand: CLASS 10A is tighter, useful for submersible or high-inertia loads where a slower trip risks winding damage. Mounts via pluggable connection onto a terminal module — no hardwiring to the base unit, which speeds swap-out during line-down maintenance. The 65 mm width and 290 mm height fit standard 35 mm DIN-rail enclosures; the 150 mm depth leaves clearance for wiring ducts and cable bends behind the panel door.
Fieldbus and I/O — what connects where
Dual-protocol onboard: PROFINET and PROFIBUS DP. That means it can drop into either an IO-controller-based line (PROFINET) or a legacy DP network without an extra gateway. The control module handles digital input signals (2 inputs,) — these are typically used for start/stop or reset commands from the PLC or a local pushbutton station. The 2-byte input and 2-byte output process data map to the starter's status and control words; you'll configure the I/O mapping in TIA Portal or STEP 7. Main energy infeed uses screw-type terminals, while the control and communication pass through the plug connector on the terminal module. If you're replacing a failed unit, the terminal module stays in the panel — you just unplug the old starter and click the new one in. No re-termination of power wiring.
Environmental and mounting conditions
Vibration resistance 2g and shock resistance 5g / 11 ms cover normal machine-mounted applications; if you're mounting it on a high-vibration press or conveyor drive, check the installation manual for additional damping requirements. Mounting position is vertical or horizontal — flexibility for tight panel layouts where a vertical rail isn't available. The pluggable terminal module means the starter can be oriented either way without worrying about gravity affecting the connection.