SIRIUS Size S0 power contactor — panel integration note
The Siemens SIRIUS 3RT1024-3AG20-ZX95 is a Size S0 power contactor rated for 5.5 kW at 400 V in AC-2 duty (slip-ring motor starting) and 7.5 kW at 690 V in AC-3 duty (squirrel-cage motor switching).
At 690 V AC-3, the contactor switches 7.5 kW, covering standard three-phase induction motors up to that power on a 690 V line. The auxiliary contact block handles 10 A at 24 V (resistive), 6 A at 230 V, and 2 A at 60 V — sufficient for PLC-level control signals and small relay coils.
Termination and coordination
Main current circuit terminals are screw-type, accepting 2x (1 to 2.5 mm²) solid or stranded, 2x (2.5 to 6 mm²), or max 2x 10 mm². For coordination type 2 (no damage to the contactor under short circuit), use a gL/gG fuse rated 25 A; for type 1 (contactor may need replacement), a 63 A fuse is permitted.