S0 frame, AC coil, three main poles
The Siemens 3RT7027-1AQ00 is a SIRIUS S0-size contactor with three normally open main contacts, rated for AC control voltage. It carries a 6 A rated operational current at 230 V in AC-3 duty — the load category for squirrel-cage motor switching — and 3 A at 400 V. The AC-3 maximum switching rate is 800 operations per hour; the heavier AC-4 duty (inching, plugging) is limited to 250 operations per hour. Pollution degree 3 (conductive pollution typical in industrial enclosures) is declared, so the contactor is suited for control panels without additional environmental sealing.
DIN-rail mounting and panel fit
Fastening is by screw and snap-on onto a 35 mm standard mounting rail per DIN EN 50022. The 45 mm width and 91 mm depth fit the S0 frame footprint; side-by-side mounting is permitted without derating, so panel fill factor is straightforward. Mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward or backward, giving flexibility in tight enclosures. The screw-type terminals on main and auxiliary circuits accept 2x (0.5 to 1.5 mm²) solid or stranded, or 2x (0.75 to 2.5 mm²) finely stranded with ferrule.
Coil, auxiliaries, and coordination
The AC magnet coil draws 0.24 A at both 50 Hz and 60 Hz. Closing power is 0.82 W DC; holding power drops to 0.24 W DC. Auxiliary switch extension is supported, and the auxiliary contacts are rated for PLC-level signals (17 V, 5 mA) — acceptable for direct input to a controller without an interposing relay. For type of coordination 2 (limited overcurrent damage), the recommended fuse is gL/gG NH 3NA: 50 A; for type of coordination 1 (no damage), the same fuse type at 125 A. Surge voltage resistance is 6 kV, and shock resistance is 12.5g for 5 ms or 7.8g for 10 ms sine pulse.