What it is and where it fits
The Siemens 3RT6028-1BB40 is a SIRIUS power contactor in the S0 frame size, designed for switching motor loads in industrial control panels. It snaps onto a 35 mm DIN rail per DIN EN 50022 or screws directly to a mounting plate, with a 45 mm width that fits standard panel layouts. Rated for AC-3 duty up to 690 V, it handles motor switching at 27.5 kW at 400 V and 47.5 kW at 690 V (both at 60 °C ambient), making it suitable for pump, fan, and compressor loads in 400 V and 690 V networks.
Key ratings and what they mean for fit
The 24 VDC coil draws 6 A at rated voltage — a standard control voltage for PLC-driven panels, but verify your DC supply can support the inrush if multiple contactors pull in simultaneously. The S0 frame size and 45 mm width mean this contactor occupies the same DIN-rail footprint as the earlier 3RT2028 series, so a panel designed around the 3RT2028-1BB40 will accept this part without rewiring or rail repositioning. Operating temperature range of -25 to +60 °C covers most indoor panel environments; storage range of -55 to +80 °C allows for unheated warehouses during transport.
Lifecycle and sourcing reality
RoHS compliance is documented with a substance prohibitance date of 05/01/2012, covering REACH and EU RoHS requirements. The contactor carries screw-type terminals for both main and auxiliary circuits, and an auxiliary switch block can be added via the product extension slot.