SIRIUS power contactor, Size S00 — 110 VDC coil, spring-loaded terminals
The Siemens 3RT1017-2BF42 is a SIRIUS power contactor in the Size S00 frame, rated for a 110 VDC coil and fitted with spring-loaded terminals on the main current circuit. It snaps onto a 35 mm DIN rail per DIN EN 50022 and occupies a 45 mm width, leaving a 6 mm side clearance for airflow between adjacent units. The front and terminal blocks carry IP20 protection, sufficient for enclosed panel environments where accidental finger contact is the main risk.
Ratings and what they mean for the buyer
The AC-4 rating at 400 V is 8.5 A — this is the motor-switching duty cycle for reversing or inching applications where the contactor makes and breaks the load under full current. For AC-2 duty (starting only, no plugging) the same contactor handles 5.5 kW at 400 V. At 500 V and 690 V the power rating holds at 5.5 kW, which tells you the contactor is thermally limited by the S00 frame size, not by voltage creepage at these levels. The magnet coil draws 3.3 W during both closing and holding — a DC coil that holds at the same power as it picks means no economizer circuit is needed, but it also means the coil stays warm continuously. Verify the 110 VDC supply can deliver the inrush without droop; the holding power is low enough for most 24 VDC-derived supplies stepped up through a DC-DC converter. Short-circuit coordination is specified with Type 1 and Type 2 requirements: Type 2 (no damage to the contactor) calls for a 20 A gL/gG fuse; Type 1 (contactor may need replacement after fault) allows a 35 A gL/gG fuse. This matters when the panel designer is coordinating with upstream motor-protective breakers or fuses.
Mounting and wiring integration
The contactor mounts via screw or snap-on onto a 35 mm DIN rail per DIN EN 50022. Side-by-side mounting is permitted, so multiple contactors can pack tightly on the rail — the 45 mm width per unit is the only horizontal space consumed. The spring-loaded terminals accept 2x (0.25 to 2.5 mm²) solid or stranded conductors, or 2x (24 to 14 AWG). Strip length is not listed in the spec, but standard practice for spring-cage terminals on this class is 8–10 mm. Operating temperature range is -25 to +60 °C, with a maximum altitude of 2 000 m without derating. Pollution degree 3 means it tolerates conductive dust and condensation typical of industrial control panels not hermetically sealed.