S0 Frame, 24 VDC Coil, Spring-Terminal Power Contactor
The Siemens 3RT2027-2BB40 is a SIRIUS power contactor in the S0 frame size, with a 24 VDC coil and spring-type terminals on both the coil and main circuits. It mounts via screw or snap-on onto a 35 mm DIN rail per DIN EN 60715, and the mounting position allows +/-180° rotation on a vertical surface plus +/-22.5° tilt forward/backward.
Switching Duty and Mechanical Life
Rated for 1,000 switching cycles per hour in AC-1 resistive duty, 750 cycles/h in AC-2 and AC-3 motor duty, and 250 cycles/h in AC-4 plugging/reversing duty. Mechanical endurance is 10 million operations typical, which suits high-cycle applications like conveyor systems or pump panels where the contactor cycles frequently.
Coil and Auxiliary Contact Ratings
The 24 VDC coil draws 10 A at pickup (inrush) and 1.1 A holding, with an operating range of 0.8 to 1.1 times rated voltage. The built-in auxiliary switch is rated 2 A at 48/60 VDC, 1 A at 110 VDC, 0.9 A at 125 VDC, and 0.3 A at 220 VDC — these are the DC-13 inductive load ratings for the auxiliary contacts. At 230 V, the contactor is rated for 5 hp motor load; at 400 V the auxiliary contacts carry 3 A.
Installation Clearances and Conductor Sizes
The S0 envelope measures 45 mm wide, 102 mm high, and 107 mm deep — the depth figure is the dimension from the DIN rail mounting surface to the furthest projection. Minimum clearance to adjacent components: 10 mm upward, 10 mm forward, 10 mm downward, and 6 mm to the side. Main circuit terminals accept solid or stranded conductors from 1 to 10 mm², and the spring terminals accept two conductors of 0.5 to 2.5 mm² each.
Environmental Range and Lifecycle Status
Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C.