The Siemens 3RT1046-3AL20 is a SIRIUS Size S3 power contactor rated for 55 kW at 500 V and 25.4 kW at 690 V in AC-3 duty, meaning it handles the inrush and breaking of standard three-phase induction motors up to that power. The 230 V 50/60 Hz coil draws the contactor in at the rated control voltage; the operating range of 0.8 to 1.1 x Us at 50 Hz and 0.85 to 1.1 x Us at 60 Hz gives the control circuit some headroom before dropout.
Fastens by screw or snaps onto 35 mm and 75 mm standard mounting rail, so it fits the usual DIN-rail layout in a control cabinet. Side-by-side mounting is permitted, which lets multiple contactors pack tightly on the rail without a mandatory air gap — useful when building a motor starter group. The IP20 rating on the front with the cover or box terminal installed means the live parts are finger-safe inside the enclosure; the terminal body itself is IP00, so the panel door or additional shrouding protects against accidental contact.
Switching frequency and mechanical endurance
Rated for 850 switching cycles per hour in AC-3 (motor) duty and 900 in AC-1 (resistive). That is about one operation every 4 seconds at the AC-3 rate — fast enough for frequent start-stop applications like conveyors or pumps with short cycle times. Arcing time of 10 to 15 ms and total make/break time of 10 to 25 ms at AC are within the range expected for a contactor this size; the auxiliary contacts (rated 10 A at 24 V down to 0.3 A at 220 V) handle pilot-duty signalling without a separate relay.