Direct-start motor starter with adjustable trip class
The 3RK1304-5KS70-2AA3 is a SIMATIC-branded motor starter configured for direct-start duty — it switches the motor directly across the line without a reversing contactor. The trip class is field-adjustable among CLASS 5, 10, 20, and 30, meaning you can match the thermal overload curve to the motor's starting profile: a high-inertia load that takes 15 seconds to accelerate needs CLASS 20 or 30; a quick-start pump can use CLASS 10. Rated short-circuit breaking capacity at 400 V is 100,000 A — that is a 100 kA SCCR, high enough to coordinate with most upstream moulded-case breakers without cascading failure under a line-to-line fault. The power dissipation with the bypass circuit engaged is 1.944 W; without bypass it is the same 1.944 W.
On-machine I/O and fieldbus integration
This motor starter carries 4 digital inputs (M12 socket per input) and no digital outputs — the inputs are sized for local feedback (e.g., motor-mounted limit switches, proximity sensors) and the outputs are handled by the internal contactor. The input data length is 2 bytes; the output data length is also 2 bytes. Dual-protocol support: PROFINET and PROFIBUS DP are both listed as supported, so the unit can be dropped into either an RT/IRT PROFINET line or a legacy DP network without a gateway. The type of assignment is 1 — a single device node on the bus.
Environmental and panel-fit specs
Enclosure rating is IP65, meaning the housing is dust-tight and protected against low-pressure water jets — suitable for on-machine mounting in washdown areas or damp environments. The unit is fastened by screw fixing (not DIN-rail snap-on) and can be mounted vertically or horizontally. Dimensions: 160 mm depth, 110 mm width, 230 mm height — plan the gland plate and enclosure depth accordingly. Pollution degree 3 means it tolerates conductive pollution (condensation, light splashes) without conformal coating inside the enclosure. Vibration resistance is 2g; shock resistance is 15g for 11 ms.