What it is and what it does
The Siemens 3RT1015-1AF01 is a SIRIUS power contactor in frame size S00, designed for switching motor loads and resistive loads in control panels. It is rated for 3 kW at 400 V in AC-2 duty (slip-ring motor starting) and 6.5 A at 400 V in AC-4 duty (plugging/inching). At 690 V it handles 4 kW, and at 24 V the rated operational current is 10 A. The contactor mounts via screw or snap-on onto a 35 mm DIN rail per EN 50022, making it a straightforward panel fit. It occupies 45 mm of DIN rail width, with a height of 57.5 mm and depth of 72 mm.
Key ratings and what they mean for your panel
The AC-2 rating of 3 kW at 400 V tells you this contactor is sized for a 3 kW slip-ring motor — the duty cycle for starting and running. The AC-4 rating of 6.5 A at 400 V covers the more severe plugging or inching cycles, where the contactor makes and breaks stalled rotor current. For general resistive loads (AC-1), the 24 V rating of 10 A gives a baseline, though the actual AC-1 current will be higher at line voltage. Mechanical endurance is rated at 30 million operations typical, meaning the contactor can handle high-cycle applications like conveyor indexing or pump cycling without early mechanical failure. The ambient temperature range of -25 to +60 °C covers most indoor panel environments, including unheated warehouses. Pollution degree 3 means the contactor is suitable for industrial environments with conductive pollution or dry non-conductive pollution that could become conductive. The IP20 rating on the front and terminals means it is touch-safe but not sealed against dust ingress — it belongs inside an enclosure.
Wiring and coordination
Main and auxiliary circuits use screw-type terminals. Wire capacity for the main contacts accepts 2x solid conductors from 0.5 to 1.5 mm², 2x from 0.75 to 2.5 mm², or a single conductor up to 4 mm². AWG equivalents are 2x 20–16, 2x 18–14, or 1x 12 AWG. The auxiliary contacts accept the same wire sizes. Short-circuit protection coordination: for Type 2 coordination (no damage to the contactor after a fault), use a gL/gG fuse rated 20 A. For Type 1 coordination (contactor may need replacement after a fault), the fuse can be 35 A gL/gG.