SIRIUS Size S2 power contactor — panel integration note
The Siemens 3RT1035-1AN60 is a SIRIUS power contactor in the Size S2 frame, rated for motor switching in AC-3 duty up to 18.5 kW at 400 V. Screw-type terminals on the main circuit accept stranded conductors up to 2x 25 mm², and the auxiliary circuit handles solid wire from 0.5 to 4 mm². Mounting is via screw or snap-on onto 35 mm DIN rail per EN 50022, with side-by-side mounting permitted — no gap required between units on the same rail. Operating temperature range is -25 to +60 °C, storage from -55 to +80 °C. Pollution degree 3 means it's rated for industrial environments with conductive contamination. The front face carries IP20 protection; the terminal area is IP00, so panel builders should account for clearance to live parts inside the enclosure.
Duty-cycle and switching frequency
Switching frequency varies by duty class: AC-1 (resistive loads) allows up to 1,200 operations per hour, AC-3 (motor starting) 1,000 ops/h, AC-2 (slip-ring motors) 600 ops/h, and AC-4 (plugging/inching) 300 ops/h. The arcing time is 10–15 ms, and the operating voltage range spans 0.8–1.1x rated at 50 Hz and 0.85–1.1x at 60 Hz.
Terminal and wire range
Main circuit terminals accept solid or stranded 2x (0.75–16 mm²) and stranded up to 2x (0.75–25 mm²). Auxiliary contacts accept solid 2x (0.5–1.5 mm²), 2x (0.75–2.5 mm²), and max 2x (0.75–4 mm²). All are screw-type terminals — no spring-cage option on this variant.