SIRIUS S3 Power Contactor for Motor Loads
The Siemens 3RT2046-3NB30 is a SIRIUS S3 power contactor designed for switching motor loads in industrial control panels. It mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715, fitting into standard panel layouts. Rated for AC-3 duty at 850 switching cycles per hour maximum, this contactor handles the high inrush of squirrel-cage motors during starting and breaking. The AC-3e rating matches the same 850 1/h ceiling, confirming consistent performance across motor-switching profiles. The coil accepts 20-33 V AC/DC, with a pick-up threshold at 0.8 of rated value and a 1.1 full-scale ceiling. Inrush current peaks at 6.5 A, while steady-state coil draw is 3.5 VA at both 50 and 60 Hz — useful for sizing the control transformer.
Wiring and Panel Integration
Main power terminals accept solid conductors from 2.5 to 16 mm² and stranded from 6 to 70 mm². Auxiliary control wiring uses 2x (0.5 to 2.5 mm²) solid or stranded. The coil connection uses spring-type terminals for fast wiring without retorquing. Physical footprint is 70 mm wide, 140 mm high, and 152 mm deep — the S3 frame size. Clearance requirements: 10 mm above and below, 10 mm to the sides, and 20 mm forward for arc venting. The mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward, giving flexibility in crowded enclosures. Operating temperature range is -25 to +60 °C; storage from -55 to +80 °C. The contactor is rated for 10 million mechanical cycles typical, with arcing time between 10 and 20 ms and operate delays of 38-57 ms for both AC and DC coils.
Duty Cycle and Auxiliary Contact Configuration
Switching frequency limits vary by duty class: AC-1 (resistive) at 900 1/h, AC-2 (slip-ring motor) at 350 1/h, AC-3 (squirrel-cage motor) at 850 1/h, and AC-4 (plugging/inching) at 250 1/h. These ceilings prevent overheating the contactor in high-cycle applications. The contactor includes an auxiliary switch block (1 NO + 1 NC configuration for main contacts, 10-2 arrangement). The auxiliary switch is present and wired separately for status feedback or interlocking. Coil suppression is built-in for the 20-33 V range. At 24 V rated value, the contactor switches 10 A; at 48 V and 60 V, 2 A; at 110 V, 1 A — these are the rated operational currents for the coil circuit under those specific voltages.
Lifecycle and Sourcing
For compliance documentation, Siemens provides standard declarations for RoHS and REACH. The contactor carries CE marking for the European market and is designed to meet IEC/EN 60947-4-1 for contactors and motor-starters.