SIRIUS S2 Power Contactor — 30 kW AC-3, 41 A AC-4
The Siemens SIRIUS 3RT1036-1BB44-3MA0 is a S2-frame power contactor rated for motor switching at 30 kW at 500 V AC-3, and for demanding AC-4 duty (plugging, inching) at 41 A at 400 V. That AC-4 figure is the one to watch if your application involves frequent reversing or jogging — it's the real-world limit for contactor life under those loads. Mounts via screw and snap-on onto 35 mm DIN rail per EN 50022. The IP20 front enclosure protects against finger contact in the panel; the terminal area is IP00, so live parts are exposed when wired — standard for panel-mount contactors.
Coil and Auxiliary Ratings
Coil rated at 24 V DC, draws 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, 0.3 A at 220 V, 6 A at 230 V, and 3 A at 400 V — these are the pick-up/hold currents across the range. Arcing time is 10 to 15 ms; DC operating time is 20 to 25 ms. The coil's minimum switching capacity is 0.8 (initial value) and 1.1 (full-scale value) — these are the thresholds below which the contactor may not reliably switch, so check your control voltage sag.
Wiring and Terminals
Main current circuit uses screw-type terminals. Solid wire: 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), max 2x (0.75 to 4 mm²). Stranded wire: 2x (0.75 to 25 mm²). Solid or stranded: 2x (0.75 to 16 mm²). Minimum permissible conductor at 40 °C is 16 mm². These are the termination limits for the main power terminals — match your cable lugs accordingly.
Dimensions and Mechanical Life
Dimensions: 55 mm wide, 112 mm high, 179 mm deep. Mechanical life typical 10,000,000 operations. Side-by-side mounting is allowed — no derating for adjacent units in the same row. Maximum switching rates: 1,000 cycles/h at AC-1, 400 at AC-2, 800 at AC-3, 300 at AC-4.