SIRIUS S00 power contactor with spring-loaded terminals
The Siemens SIRIUS 3RT1015-2GG28-0NA4-ZX95 is a size S00 power contactor rated for motor switching at 4 kW at 690 V AC-3 and 3.5 kW at 500 V AC-3. The main current circuit uses spring-loaded terminals accepting 2x (0.25... 2.5 mm²) solid or stranded wire, which speeds panel wiring compared to screw terminals and holds up better under vibration. The integrated surge suppressor uses full-wave rectification, meaning the coil drive includes a built-in suppression circuit that handles the inductive kick without requiring an external varistor or RC snubber. This simplifies wiring and reduces panel clutter.
The AC-3 rating of 4 kW at 690 V defines the motor-switching capability for squirrel-cage motors — starting and disconnecting under load. At 500 V the same duty yields 3.5 kW. For resistive or lightly inductive loads (AC-1), the contactor handles up to 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V. These are the currents the main contacts can make and break without excessive wear. The AC-4 rating of 6.5 A at 400 V covers inching and plugging duty — frequent starts and reversals that generate more arc energy than AC-3. If your application involves jogging or reversing under load, this is the rating to size against.
The auxiliary contact block (1 N/O instantaneous) is integrated, and the terminal design allows for solid or stranded wire up to 2.5 mm² (AWG 14). The clearance to adjacent components on the side is 6 mm.