SIRIUS Size S2 power contactor — 3RT1035-1AG20-ZX95
The Siemens 3RT1035-1AG20-ZX95 is a SIRIUS power contactor in the Size S2 frame, rated for motor switching at 22 kW at 500 V AC-3 and 18.5 kW at 400 V AC-2.
The AC-3 rating of 22 kW at 500 V governs motor switching under full-load running conditions — that's the number to match against your motor nameplate for induction motors up to that power. For resistive loads (AC-1), the contactor can cycle up to 1,200 operations per hour; AC-3 allows 1,000 per hour, and AC-4 (plugging/reversing) drops to 300 per hour — the thermal limit of the arc chamber, not the coil. DC switching is specified across several voltages: 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, 0.3 A at 220 V, 6 A at 230 V, and 3 A at 400 V. These are the make/break limits for DC loads, which arc differently than AC — the contact gap and arc chute are sized for these values. If you're switching a DC solenoid or brake coil, stay within the row that matches your circuit voltage. The operating range factor is 0.8–1.1 at 50 Hz and 0.85–1.1 at 60 Hz — meaning the coil holds in across 80–110% of rated control voltage at 50 Hz, and 85–110% at 60 Hz. Below those thresholds, the contactor may drop out or chatter. Arcing time runs 10–15 ms, and the AC make/break time is 7–20 ms, which matters for coordination with upstream short-circuit protection.
Mounting and wiring in the enclosure
Dimensions are 55 mm wide, 112 mm high, and 115 mm deep, which fits standard S2 cutouts in most motor control centers. Terminals accept solid conductors: 2x (0.5–1.5 mm²), 2x (0.75–2.5 mm²), max 2x (0.75–4 mm²). Stranded goes up to 2x (0.75–25 mm²), and the combined solid/stranded range is 2x (0.75–16 mm²). That covers most panel wiring up to 4 AWG for the power circuit.