SIRIUS S2 power contactor for motor switching
The Siemens SIRIUS 3RT1036-3BB40-ZX95 is a power contactor in the S2 frame size, designed for switching motor loads in control panels. Its 24 VDC coil draws 10 A at rated voltage, and the contactor is rated for 30 kW at 500 V AC-3 duty — the rating that governs motor switching. At 690 V AC-3 it delivers 11.4 kW, and at 400 V AC-2 it handles 22 kW. The AC-4 rating at 400 V is 41 A, covering reversing or inching applications. Mounting is via screw and snap-on onto a 35 mm DIN rail per DIN EN 50022, with side-by-side mounting permitted. The enclosure carries IP20 on the front and IP00 at the terminals — meaning the wiring area is not sealed against dust ingress, so it belongs inside a panel, not in a washdown zone.
Terminal and wiring details
Main circuit terminals are screw-type, accepting 2x solid conductors from 0.25 to 2.5 mm² or 2x stranded from 0.75 to 25 mm². The minimum permissible cross-section at 40 °C is 16 mm². Coil terminals accept 2x solid or stranded 0.75 to 16 mm².
Switching frequency and environmental limits
Maximum switching rates: 1 000 cycles/hour at AC-1, 800 at AC-3, 400 at AC-2, and 300 at AC-4. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C. Arcing time is 10 to 15 ms, and the DC dropout delay is 20 to 25 ms. Mechanical life is typically 10 million operations.