SIRIUS reversing starter with AS-Interface
The Siemens 3RK1325-6KS41-1AA5 is a SIRIUS reversing motor starter designed for direct-on-line reversing of three-phase motors up to 0.75 kW at 400 V (0.7 hp at 460/480 V, 1 hp at 575/600 V). It integrates the reversing contactor pair, overload protection, and AS-Interface communication into a single IP65-rated enclosure — no separate control cabinet needed for distributed motor control. The AS-Interface protocol connection handles addressing via an M12 plug, with four digital inputs available for local sensors or pushbuttons. Supply voltage is 24 V DC (20.4…28.8 V range), and the unit draws its logic power from the AS-i bus or an auxiliary 24 V feed.
Trip class and motor protection
The overload relay is field-selectable among trip classes 5, 10, 15, and 20. Class 10 is the standard motor-protection setting for general-purpose induction motors; Class 20 accommodates high-inertia loads like fans or centrifuges where start time exceeds 10 seconds. Class 5 is used for fast-acting protection on short-start applications or submersible pumps. ON-delay is 85 ms, OFF-delay 65 ms — these are the internal response times for the reversing contactor pair, not the overload trip curve. The unit supports both direct start (via the reversing contactors) and reverse starting, but does not include a separate direct-start contactor; reversing is inherent to the design.
Rated IP65, the enclosure is suitable for washdown environments and outdoor installation where hose-directed water is present. Shock resistance is 12 g / 11 ms, vibration resistance 7 mm / 2 g — adequate for machine-mounted applications on conveyors, packaging lines, or pump skids. Mounting is via screw fixing in any orientation — vertical, horizontal, or flat — though horizontal is recommended for optimal heat dissipation from the power semiconductors. Dimensions are 294 mm wide × 215 mm high × 159 mm deep. The main power connection uses a HAN Q4/2 plug per ISO 23570; the AS-Interface and digital inputs connect via M12 plugs.
The part carries no UL or CSA listing in the available evidence; compliance documentation (RoHS, REACH) should be requested from the manufacturer or distributor at time of order.