The Siemens 3RT7036-1AC20 is a Size S2 contactor from the SIRIUS family, built for switching three-phase motor loads up to 690 V AC-3. It carries three normally-open main contacts and a 24 V 50/60 Hz coil.
The AC-3 rating at 690 V maximum tells you this contactor is sized for motor switching, not just resistive loads. The 6 kV rated surge voltage resistance means it handles transient overvoltages common on industrial mains without flashover. Insulation voltage is also 690 V, so it can be used on 400 V or 480 V systems with full margin. Shock resistance of 15g at 5 ms and 8g at 10 ms (sine pulse) confirms it can survive shipping and moderate machine vibration.
The degree of pollution is rated 3, so it's suitable for environments with conductive dust or humidity — typical for industrial control panels. The front face carries IP20 finger protection; the terminals are IP00, meaning they rely on the enclosure for touch safety.
Both main and auxiliary/control circuits use screw-type terminals.