What this contactor is and what it does
The Siemens 3RT1015-1BF41 is a SIRIUS power contactor in size S00, built for switching motor loads and resistive loads in control panels. It mounts via screw or snap-on onto 35 mm DIN rail per EN 50022, so it drops straight into a standard panel layout without adapter brackets. The coil is rated 110 V DC, drawing 3.3 W for both closing and holding. Switching capacity depends on duty. In AC-3 motor starting at 400 V it handles 3 kW; in AC-4 (inching/plugging) at 400 V it's rated 6.5 A. For resistive loads (AC-1 / AC-12) the main contacts carry up to 10 A. The 1 NC auxiliary contact is built in — no add-on block needed for a basic feedback signal.
Mounting and integration into a panel
At 45 mm wide, 57.5 mm tall, and 72 mm deep, the S00 footprint fits tightly on a DIN rail — side-by-side mounting is allowed. The 6 mm clearance to adjacent devices on the side is the minimum for heat dissipation. Terminals are IP20 finger-safe screw-type, accepting 2x (0.5 to 1.5 mm²) solid or 2x (0.75 to 2.5 mm²) stranded, max 2x 4 mm². For AWG: 2x (20 to 16) solid, 2x (18 to 14) stranded, single 12 AWG. Strip length and torque are standard for this terminal class — the panel wireman will recognize the cage. Pollution degree 3 means it's rated for industrial environments where conductive dust or occasional condensation occurs — no extra conformal coating needed for a typical IP20 cabinet.
Short-circuit coordination and protection
For Type 2 coordination (no damage to the contactor after a fault), the required upstream fuse is gL/gG 20 A. For Type 1 coordination (contactor may need replacement but no hazard), fuse gL/gG 35 A. That's the sizing rule for the panel builder: match the fuse to the coordination type your spec calls for.