SIRIUS Size S2 Power Contactor — 3RT1035-1BB44-ZM96
The Siemens 3RT1035-1BB44-ZM96 is a SIRIUS power contactor in the Size S2 frame, rated for motor switching at 22 kW at 500 V (AC-3) and 18.5 kW at 400 V (AC-2), with an AC-4 breaking current of 35 A at 400 V for reversing or inching duty. The main current circuit uses screw-type terminals, and the contactor mounts via screw or snap-on onto a 35 mm DIN rail per DIN EN 50022, with side-by-side mounting permitted for dense panel layouts. Front-of-device protection is IP20; the terminal area is IP00, so panel builders should account for finger-safe shrouding or clearance in the wiring compartment.
Ratings and Duty Cycles
AC-1 resistive switching supports up to 1,200 operations per hour, while AC-3 motor duty allows 1,000 ops/h. The more severe AC-4 category (plugging, inching) is rated at 300 ops/h, reflecting the higher electrical stress on the contacts during reversal or jogging. Mechanical endurance is rated at 10 million operating cycles typical, which aligns with the SIRIUS platform's expected service life for high-cycle conveyor or pump applications. Coil pickup and dropout timing: at DC the contactor closes in 20 to 25 ms and the arcing time is 10 to 15 ms, giving a predictable sequence for safety-circuit interlocking.
Environmental and Compliance
Operating ambient temperature range is -25 to +60 °C, with storage from -55 to +80 °C. Pollution degree 3 (conductive pollution, typical for industrial control panels) is specified, so no additional conformal coating is required for normal factory-floor environments. RoHS compliance date is noted as May 1, 2012, indicating the part meets the EU RoHS substance restrictions effective from that date.
Termination and Wiring
Main circuit terminals accept solid or stranded conductors: 2x (0.75 to 16 mm²) for the power path, with a minimum permissible cross-section of 16 mm² at 40 °C for full-rated current. Auxiliary/control terminals accept solid wire: 2x (0.5 to 1.5 mm²) and 2x (0.75 to 2.5 mm²), with a maximum of 2x (0.75 to 4 mm²). Stranded terminations on the control side accept 2x (0.75 to 25 mm²). Dimensions: 112 mm height, 55 mm width, 179 mm depth — the depth is the key constraint when fitting into shallow enclosures or behind gland plates.