Integrator note — 3RT1044-1AQ24
The Siemens 3RT1044-1AQ24 is a SIRIUS S3 power contactor rated for motor switching at 37 kW at 500 V AC-3 (50/60 Hz). It handles 18.6 kW at 690 V AC-3, so the voltage class determines the kW limit — at 500 V you get the full 37 kW; at 690 V it derates to 18.6 kW. That's the number to check against your motor nameplate.
Mounting and wiring
Snaps onto 35 mm or 75 mm standard mounting rail — screw and snap-on fastening method. Side-by-side mounting is allowed, so you can gang multiple contactors without a gap. Dimensions: 146 mm high, 70 mm wide, 188 mm deep. The main circuit uses screw-type terminals; stranded wire up to 2x 50 mm² or solid up to 2x 4 mm². Control terminals accept 0.5 to 4 mm² solid or stranded.
Environmental and protection
Front face carries IP20 protection (with cover or box terminal); the terminal area itself is IP00 — keep fingers and tools clear when live. Pollution degree 3 (conductive pollution or dry non-conductive that becomes conductive due to condensation). Operating temperature -25 to +60 °C; storage -55 to +80 °C.
Switching performance
AC operating time (closing) is 10 to 19 ms; arcing time 10 to 15 ms. Maximum switching rates: 1000 cycles/hour at AC-1 or AC-3, 400 at AC-2, 300 at AC-4. Typical mechanical life is 10 million operations. Pickup voltage range 0.8 to 1.1 x rated at 50 Hz, 0.85 to 1.1 at 60 Hz.