SIRIUS S0 power contactor, 24 VDC coil — what you need to know on the van
The Siemens 3RT2027-1NB30-ZX95 is a SIRIUS power contactor in the S0 frame size, built for switching motor loads in control panels and industrial machinery. It carries a 24 VDC coil (rated value 21...28 V) with screw-type terminals on both coil and main contacts — field-serviceable with standard tools, no special crimper needed. Mounts via screw or snap-on onto 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 — handy when you're wedging this into a crowded panel on site. Operating temperature range is -25 to +60 °C during operation, storage from -55 to +80 °C, so it handles the thermal swings you get in unventilated enclosures or outdoor cabinets.
Coil draw and switching cycles
Inrush current peak at 24 V rated value is 10 A, holding at 1.3 A full-scale — that's the sealed current. The coil power factor sits at 0.86 at 50 Hz, 0.82 at 60 Hz. Arcing time is tight at 10 ms, and operating times run 30...50 ms on AC, 35...50 ms on DC. Mechanical life of the contactor is typical 10 million operations. Maximum switching rates vary by duty: AC-1 (resistive) at 1,000 cycles/hour, AC-3 (motor start/run) at 750 cycles/hour, AC-4 (plugging/inching) at 250 cycles/hour. The AC-3e rating also sits at 750 cycles/hour.
Wiring and clearances
Main contact wiring accepts solid or stranded conductors from 1 to 10 mm². Auxiliary contacts take 2x (0.5...1.5 mm²) or 2x (0.75...2.5 mm²) solid or stranded. The contactor includes an auxiliary switch as standard. Clearance requirements: 10 mm upwards, 10 mm forwards, 10 mm downwards, 6 mm at the side. Overall dimensions are 85 mm height, 45 mm width, 107 mm depth — the depth figure matters when you're checking gland-plate clearance in a shallow enclosure.