SIRIUS S2 power contactor — what it is and what it handles
The Siemens 3RT1034-3AU00 is a SIRIUS power contactor in the S2 frame size, designed for motor switching in control panels. It mounts via screw or snap-on onto 35 mm DIN rail per EN 50022, and its side-by-side mounting capability keeps panel layouts dense. Rated for 15 kW at AC-2 duty at 400 V — that's the category for starting and stopping slip-ring motors or wound-rotor loads where the contactor closes before the motor reaches full speed. For plugging or inching (AC-4), it carries 29 A at 400 V, which covers reversing or jogging applications where the contactor makes and breaks stalled-rotor current. At 500 V it delivers 18.5 kW, and at 690 V it delivers 10 kW, so it suits 480 V and 600 V class systems common in North American and export panels.
Termination and wiring constraints
Main current circuit uses screw terminals. Solid conductors accept 2x (0.25 to 2.5 mm²); stranded accepts 2x (0.75 to 25 mm²). The larger stranded range means you can land a 16 mm² feed at 40 °C ambient without an adapter — that's the minimum permissible cross-section at that temperature. Front face is IP20 (finger-safe), terminals are IP00 — open terminal protection, so panel builders need to account for clearance in the enclosure layout. Pollution degree 3 means it's rated for conductive pollution environments typical of industrial control rooms.
Mechanical envelope and operating conditions
Dimensions: 112 mm high, 55 mm wide, 115 mm deep. That 115 mm depth is the dimension that matters for gland-plate clearance and enclosure depth selection — it's the distance from the DIN rail backplane to the farthest terminal projection. Operates from -25 °C to +60 °C; storage range is -55 °C to +80 °C. Coil draw at 24 V is 10 A, at 60 V is 2 A, at 110 V is 1 A, at 220 V is 0.3 A — these are the steady-state holding currents, not inrush. Mechanical life is 10 million operations typical.