SIRIUS S2 Power Contactor, 48 VDC Coil
It carries a 48 VDC coil rated for continuous duty, with a pickup threshold of 0.8x rated voltage and dropout at 1.1x rated voltage — meaning the coil pulls in reliably at 38.4 V and drops out at 52.8 V, giving a clean margin against brownout conditions on a 48 V control bus. Rated for 22 kW at 500 V in AC-3 duty (squirrel-cage motors) and 18.5 kW at 400 V in AC-2 duty (slip-ring motors), this contactor handles the majority of 20–30 hp motor starts in a 400 V or 480 V plant. The front face carries IP20 finger protection; the terminals are IP00, meaning the wiring compartment must be inside a closed panel or enclosure.
Main current circuit terminals are screw-type, accepting stranded conductors from 2x 0.75 mm² up to 2x 25 mm², and solid conductors from 2x 0.5 mm² up to 2x 4 mm². The minimum permissible cross-section at 40 °C ambient is 16 mm² for the main circuit — a useful detail when sizing branch feeders for a 22 kW motor on a hot panel floor. Coil terminals accept 2x 0.75 to 2x 2.5 mm² solid or stranded, with a strip length appropriate for screw-clamp termination. The 55 mm width and 112 mm height fit the standard S2 footprint, and the 179 mm depth leaves clearance for wiring ducts and finger-safe covers in a 200 mm deep enclosure.
Compliance documentation includes RoHS conformity dated to 05/01/2012 (substance prohibitance date), and the product carries the usual Siemens CE, UL, and CSA certifications for the SIRIUS contactor family.
Switching Performance and Life
Electrical life varies by duty: AC-1 (resistive) allows up to 1,200 switching cycles per hour, AC-3 (motor start) allows 1,000 cycles/hour, and AC-4 (plugging/inching) is limited to 300 cycles/hour due to the higher arc energy at each break. Arcing time is 10 to 15 ms, and DC operating time (pickup + dropout) is 20 to 25 ms — fast enough for most PLC-controlled sequences but worth noting if the contactor is used in a time-critical safety circuit where the total break time must be under 50 ms.
Environmental Range
The wide storage range is typical for SIRIUS contactors and allows the part to be kept in unheated warehouses or shipped in cold climates without damage.