The Siemens 3RT1517-1BM40 is a SIRIUS power contactor in the compact Size S00 frame, built for switching motor and resistive loads in control panels up to 690 V. It carries a 24 V DC coil rated to pull in at 85 % of nominal voltage (20.4 V) and hold, with a dropout time of 7 to 10 ms once the coil voltage decays below the dropout threshold. The main contacts are rated for 10 A at 24 V DC in DC-13 duty, and the auxiliary contacts — one NO and one NC — each handle 12 A continuously. Mechanical life is rated at 30 million operations typical, so this contactor holds the unit on the grid for a long run between overhauls, provided the switching frequency stays within the 1 000 cycles per hour maximum for AC-1 loads.
The 45 mm width and 72 mm depth fit standard DIN-rail enclosures; side-by-side mounting is permitted with a 6 mm clearance to adjacent devices on each side for heat dissipation. The vertical mounting surface allows ±180° rotation and ±30° tilt front-to-back, so panel layout is flexible as long as the operating temperature range of -25 to +60 °C is respected. Wire entry accepts 2 × (0.5 to 1.5 mm²) solid or 2 × (0.75 to 2.5 mm²) stranded, with a maximum of 2 × (0.75 to 4 mm²) — spring-cage not fitted here, screw terminals on the main circuit require a PZ1 bit and 0.8 N·m torque.
Switching performance and protection
Arcing time runs 10 to 15 ms under rated load; the 6 kV impulse withstand voltage on both main and auxiliary circuits (per IEC 60947-1) gives decent margin against transient overvoltages in industrial networks. The contactor is rated for operation up to 2 000 m altitude without derating.