What it is and what it does
The Siemens 3RT1016-2KF41 is a SIRIUS power contactor in frame size S00, built for switching motor loads in industrial control panels. The 110 V DC coil draws 2.3 W for both closing and holding, and the integrated varistor suppresses the switching transient — no external suppressor needed on the coil circuit. Spring-loaded terminals on the main circuit accept 2x (0.25... 2.5 mm²) solid or stranded wire, so the wireman lands the power leads without a screwdriver. Rated for motor duty: at AC-3, 400 V it handles 4.5 kW; at 690 V, 5.5 kW. The AC-4 rating at 400 V is 8.5 A for reversing or inching applications where the contactor makes and breaks the load under full current. Mechanical life is 30 million operations typical, so this is a workhorse for high-cycle conveyor or pump stations.
Panel fit and mounting
Snap-on mounting onto 35 mm DIN rail per EN 50022, or screw-mount through the base. At 45 mm wide and 73 mm deep, it fits a standard 45 mm slot in a motor starter row. Side-by-side mounting is allowed with 6 mm clearance at the side for heat dissipation. IP20 on the front and terminals means it's protected against finger contact — standard for enclosed panels, not for washdown zones.
Coordination and protection
Type 2 coordination (no damage to the contactor on a short circuit) requires a gL/gG fuse rated 20 A. Type 1 coordination (contactor may need replacement after fault) allows a 35 A fuse. The coil circuit includes a varistor as standard — no extra surge suppressor to order. Pollution degree 3 suits the part for industrial environments with conductive dust or humidity.