The 3RT2027-1AN20: This is a SIRIUS S0-frame power contactor — the S0 frame is the compact workhorse for motor loads up to roughly 7.5 kW at 400 V AC-3. The 45 mm width and 85 mm height fit standard 35 mm DIN rail (DIN EN 60715) with screw and snap-on fastening, so it occupies one 45 mm module in a panel. The main contact wiring accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded. The auxiliary switch is included (screw-type terminals).
S0 Frame — What It Carries
The S0 frame size tells you the physical envelope and the current range this contactor is built for. It is the smallest of the SIRIUS contactor frames (S0, S2, S3, S6, S10, S12), sized for motor currents up to about 16 A AC-3 at 400 V. That makes it a direct fit for small motor starters, pump panels, and conveyor drives in the 4–7.5 kW band. The 45 mm width means three of these fit in a standard 140 mm DIN-rail segment, leaving room for an overload relay alongside.