SIRIUS S2 power contactor — 3RT5035-1AN20
The Siemens 3RT5035-1AN20 is a SIRIUS S2-size power contactor rated for motor switching at 38 kW at 400 V at 60 °C ambient, or 66 kW at 690 V at 60 °C. Screw-type terminals on the main circuit accept 2x (0.75 to 16 mm²) solid or stranded, with an AWG equivalent of 2x (18 to 2). Rated operational current in AC-3e duty is not directly listed, but the 38 kW at 400 V figure places it in the range of a 65–75 A AC-3 contactor — sized for a 75 hp (55 kW) motor at 400 V under standard conditions. The 690 V rating at 66 kW confirms it handles higher-voltage motors without derating the power class.
Side-by-side mounting is permitted with no derating gap required. Dimensions: 55 mm wide, 112 mm high, 115 mm deep. The S2 footprint is the mid-size in the SIRIUS contactor family — wider than the S0 (45 mm) but narrower than the S3 (70 mm). Fits standard 600 mm wide enclosures with room for auxiliary contact blocks on the front or side.
Coil and auxiliary contact ratings
The auxiliary contact block (integrated or add-on) is rated 6 A at 24 V, 6 A at 230 V, 3 A at 400 V, and 1 A at 110 V. The 220 V rating drops to 0.3 A — a non-linear derating typical of DC-interrupting contacts. For 50/60 Hz control supplies, the coil draws 0.35 A at both frequencies. Electrical life depends on duty: 5 000 operations per hour at AC, up to 1 200/h in AC-1 (resistive), 1 000/h in AC-3 (motor start/run), and 300/h in AC-4 (plugging/inching). The lower AC-4 figure reflects the higher arc energy during reversing or jogging cycles.
Substance prohibitance per RoHS applies from March 1, 2017 — the part complies with the EU RoHS recast (2011/65/EU) and its amendments. Insulation voltage rated at 690 V, matching the maximum AC-3e operating voltage.