What it is and what it does
The Siemens 3RT1036-1BB44 is a SIRIUS power contactor in the S2 frame size, designed for switching motor loads and resistive loads in industrial control panels. It carries a 24 VDC coil rated to pull in at 0.8 x nominal (19.2 V) and hold at 1.1 x nominal (26.4 V), with a coil draw of 10 A at 24 V rated value. The headline motor-switching capacity is 30 kW at 400 V in AC-3 duty (squirrel-cage motors, starting and disconnecting under load), and 22 kW at 400 V in AC-2 duty (slip-ring motors, starting and switching off at rated speed). For heavy jogging or plugging duty, the AC-4 rating at 400 V is 41 A. Mechanical life is rated at 10 million operations typical, with maximum switching frequencies of 800 cycles/hour in AC-3, 400 in AC-2, and 300 in AC-4. The arcing time is 10 to 15 ms.
Mounting and integration
Mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 50022. Side-by-side mounting is permitted without derating, which simplifies multi-contactor panels. Dimensions are 55 mm wide, 112 mm high, 179 mm deep — the depth is the dimension that extends into the enclosure, so a 200 mm deep gland plate or back panel is the practical minimum. The front of the contactor carries an IP20 rating (finger-safe terminals), while the connection area below the terminals is IP00 — meaning the bottom of the contactor where wires enter is not touch-protected. Pollution degree 3 (conductive pollution, typical for industrial environments) is the design basis. Main power terminals accept screw-type connections: solid conductors 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), max 2x (0.75 to 4 mm²); stranded conductors 2x (0.75 to 25 mm²); and solid or stranded 2x (0.75 to 16 mm²). The minimum permissible cross-section at 40 °C is 16 mm² for the main circuit.
Operating environment and compliance
Auxiliary contact ratings: at 24 VDC 10 A, 60 VDC 2 A, 110 VDC 1 A, 220 VDC 0.3 A, 230 VAC 6 A, 400 VAC 3 A, 500 VAC 30 kW, 690 VAC 11.4 kW.