SIRIUS S00 power contactor — 24 VDC coil, integrated varistor
The Siemens 3RT1016-1DB44-0KV0 is a SIRIUS-brand power contactor in the S00 frame size, designed for screw and snap-on mounting onto 35 mm DIN rail per EN 50022. The 24 VDC coil draws 3.3 W holding power, and the integrated varistor surge suppressor clips the turn-off spike — no external snubber needed across the coil terminals.
Ratings that govern the fit
For the main power circuit, the contactor is rated 10 A in AC-12 duty (resistive loads at line frequency). That is the continuous current limit for general switching; for motor loads the rating depends on duty cycle and voltage — at 500 V the contactor handles 4.5 kW in AC-3 duty, and at 690 V it handles 5.5 kW. The AC-4 rating (plugging / inching) at 400 V is 8.5 A, so if your application requires frequent reversals, that figure governs the thermal limit, not the AC-12 number. Auxiliary contacts are rated for switching at multiple control voltages: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, and 0.3 A at 220 V DC. The DC switching capacity drops sharply with voltage — the 220 V DC rating of 0.3 A reflects the arc-extinction limits of the air gap, so do not assume the AC rating carries over to DC circuits.
Coordination and protection
For type 1 coordination (no damage to the contactor after a short circuit, but it may need replacement) Siemens specifies a gL/gG fuse of 35 A. For type 2 coordination (contactor remains operable after a fault) the requirement is a 20 A gL/gG fuse. The terminal block accepts solid or stranded conductors: 2x 0.5–1.5 mm², 2x 0.75–2.5 mm², or a maximum of 2x 0.75–4 mm² per clamp.
Environmental limits and mounting
Operating temperature range is -25 to +60 °C, with a maximum altitude of 2000 m without derating. The enclosure is rated IP20 on the front and at the terminals — finger-safe but not protected against moisture ingress, so it belongs inside a sealed panel, not on an open machine frame. Pollution degree 3 (conductive pollution or dry non-conductive that becomes conductive) is the rated environment, typical for industrial control panels. Side-by-side mounting is permitted with 6 mm clearance at the sides.