What it is and where it fits
The Siemens 3RT7035-1AP00 is a Size S2, 3-pole contactor from the SIRIUS family, rated for AC-3 and AC-3e switching up to 690 V. It mounts on 35 mm DIN rail per DIN EN 50022 via screw and snap-on fastening, or can be screw-mounted directly to a panel backplate. The 55 mm width and 115 mm depth fit standard enclosure layouts — side-by-side mounting is supported, so you can gang multiple contactors without derating for heat buildup.
Key ratings and what they mean for your panel
Three main NO contacts handle the load circuit. The contactor is rated for AC-3 (squirrel-cage motor switching) and AC-3e up to 690 V. For type of coordination 2, the recommended upstream fuse is 80 A gL/gG NH 3NA; for type 1 coordination, 125 A. That gives you headroom for selectivity with downstream motor starters. The auxiliary contacts are rated for PLC-level signals — 17 V, 5 mA minimum switching capability — so you can wire them directly to a digital input card without worrying about contact wetting. Coil consumption is modest: 0.78 W closing power, 0.42 W holding power at DC. That keeps the heat rise in a crowded panel manageable. The magnet coil is DC-operated; verify your control voltage polarity and free-wheel diode placement if you're paralleling with inductive loads. Surge voltage resistance is 6 kV, which covers most industrial environments without additional MOVs.
Mounting and environmental constraints
Mounting position is flexible: +/-180° rotation on a vertical surface, and can be tilted forward/backward by +/-22.5°. Operating temperature range is -10 to +55 °C; storage from -25 to +70 °C. The front face carries an IP20 rating (finger-safe), while the terminal area is IP00 — so keep live parts behind a panel door or cover. Pollution degree 3 means it's suitable for conductive environments like factory floors. Screw-type terminals on both main and auxiliary circuits accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded wire, with core-end ferrules supported. Mechanical switching frequency: up to 800 operations per hour under AC-3, 250 per hour under AC-4.