S2 Contactor for Motor Loads
The Siemens 3RT7035-1AN20 is a size S2 contactor with three main poles for the main current circuit, rated for AC-3 duty up to 690 V maximum. That 690 V AC-3 ceiling covers standard 400 V and 480 V motor feeds with headroom for 690 V line applications. The insulation voltage is also rated 690 V, so the contactor's internal clearances are designed for that voltage class. Mounting is via screw fixing or snap-on onto 35 mm standard mounting rail per DIN EN 50022. The 55 mm width fits a standard 55 mm-wide DIN-rail footprint — no surprises in panel layout. Side-by-side mounting is permitted, so you can gang multiple contactors without spacing gaps. The front face carries an IP20 rating; the terminal area is IP00. That means the enclosure protects against finger contact on the front, but the wiring zone is open — standard for panel-mounted contactors where the cabinet provides the outer IP barrier.
Coil and Control Circuit
The magnet coil draws 0.73 W DC during closing and 0.41 W DC holding. That low holding power keeps heat dissipation minimal in a crowded enclosure. The control circuit uses screw-type terminals; auxiliary switch expansion is supported via the product extension option. Surge voltage resistance is rated at 6 kV, which aligns with IEC 60947-1 overvoltage category III for industrial control panels. Shock resistance is specified at 15 g for 5 ms and 8 g for 10 ms sine pulse — relevant if the contactor is mounted on a vibrating machine base or in a mobile application.
Environmental and Mounting Flexibility
Operating temperature range is -10 to +55 °C; storage range is -25 to +70 °C. The mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward or backward. That flexibility helps when routing cables in tight cabinets — you can orient the contactor to keep the terminals accessible. Degree of pollution is rated 3, meaning the contactor is designed for conductive pollution environments typical in industrial enclosures — not clean-room or sealed-panel duty without additional protection.