SIRIUS S2 power contactor — 3RT1034-1AH04
The Siemens 3RT1034-1AH04 is a SIRIUS power contactor in size S2, rated for motor switching at 18.5 kW at 500 V AC-3 and 10 kW at 690 V AC-3. It mounts on a 35 mm DIN rail per DIN EN 50022 via screw and snap-on fastening, and accepts screw-type terminals for the main current circuit. The front face carries an IP20 rating; the terminal area is IP00. Pollution degree 3 means it tolerates conductive pollution in industrial enclosures.
What the ratings mean for panel fit
At 55 mm wide, 112 mm tall, and 164 mm deep, the S2 frame fits standard 55 mm-wide contactor slots in motor control centers. The 18.5 kW AC-3 rating at 500 V governs motor switching for pumps, fans, and compressors up to that load; the 10 kW rating at 690 V applies where line voltage runs higher. AC-4 at 400 V is rated 29 A — that's the inching or plugging duty cycle, not continuous running. The 50 Hz operating range of 0.8 to 1.1 times rated voltage means the coil holds in on a sagging line down to about 38 V for a 48 V coil.
Wiring and terminal capacity
Screw terminals accept solid conductors from 2x 0.5 mm² up to 2x 4 mm², and stranded from 2x 0.75 mm² up to 2x 25 mm². For the main circuit, solid or stranded wire from 0.75 mm² to 16 mm² is accepted. At 40 °C ambient, the minimum permissible conductor cross-section is 16 mm² — that's the thermal derating floor for full rated current. Side-by-side mounting is allowed with no derating penalty, which simplifies panel layout.
Switching rates and mechanical life
Maximum switching rates: 1,200 cycles/hour at AC-1 (resistive), 750 at AC-2 (slip-ring motors), 1,000 at AC-3 (squirrel-cage motors), and 250 at AC-4 (inching/plugging). Typical mechanical life is 10 million operations. Arcing time runs 10 to 15 ms; operating time at AC is 7 to 20 ms. Storage temperature range is -55 to +80 °C; operating ambient is -25 to +60 °C.