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.
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.