What this SIRIUS S0 contactor is and where it fits
The Siemens 3RT2027-2BB40-ZX95 is a SIRIUS power contactor in the S0 frame size, built for switching motor loads and resistive circuits in control panels. It carries a 24 V DC coil with spring-type terminals — no screwdriver needed for the coil connection, which saves a few seconds per wire on a build-out. The contactor snaps onto 35 mm DIN rail per EN 60715 and can also be screw-mounted; the mounting position allows ±180° rotation on a vertical surface plus ±22.5° tilt forward and back, so it fits tight enclosures without forcing the bus. Rated operating current for the main contacts isn't listed directly, but the switching frequency tells the duty story: 1000 operations per hour at AC-1 (resistive), 750 at AC-2 and AC-3 (motor start/run), and 250 at AC-4 (plugging/inching). That AC-3 ceiling of 750 ops/h is typical for a general-purpose motor contactor — enough for a conveyor or pump cycling every few seconds, but not for a high-speed pick-and-place. Mechanical life is rated at 10 million operations typical, which lines up with the S0 frame's expected endurance in a clean panel.
Terminal and wiring detail — spring-cage on the coil, screw on the main
Coil connection uses spring-type terminals. Main contacts accept 1 to 10 mm² solid or stranded. Auxiliary switch terminals accept 2x 0.5 to 2.5 mm². Clearance distances are tight: 10 mm upwards, forwards, and downwards, and 6 mm at the side. In a packed panel, that means you can butt this contactor against the next device or the gland plate as long as you respect the 6 mm side gap. The 45 mm width is standard for the S0 frame — it takes one DIN module, so you're not losing rail space.
Coil and auxiliary contact ratings
Coil picks up at 0.8 x rated voltage and drops out at 1.1 x rated. Drop-out time on DC is 15 to 17.5 ms; arcing time is 10 ms. The integrated auxiliary switch is rated for 10 A at 24 V, 2 A at 48 V and 60 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, and 3 A at 400 V. It also carries a 5 hp rating at 230 V. That covers most PLC input and pilot-duty loads without needing a separate auxiliary block.
Lifecycle and sourcing posture
This part is current production. Sourced to order against an RFQ through independent distribution; availability and pricing confirmed at quote time.