What it is and what it does
The Siemens 3RH1140-1AP60 is a SIRIUS auxiliary contactor, size S00, with four normally open instantaneous contacts. It is used to switch control signals and auxiliary loads in motor control centers and industrial panels — the contacts follow the main contactor armature without delay. Rated 10 A at 24 V, it handles the typical PLC output or relay coil loads in a 24 VDC control loop; at 230 V the rating drops to 6 A, and at 400 V to 3 A, so the voltage derating curve matters when wiring across phases.
Mounting and integration
Snap-on mounting to a 35 mm DIN rail, or screw-fix directly to a backplate. The S00 footprint — 45 mm wide, 57.5 mm tall, 72 mm deep — fits the standard SIRIUS grid; it occupies one 45 mm slot on the rail. Mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward, so it adapts to tight enclosures without derating. IP20 on the front means it is protected against solid objects larger than 12.5 mm but not against moisture — keep it inside a sealed cabinet.
Wiring and contact ratings
Terminals accept solid conductors: 2x 0.5–1.5 mm², 2x 0.75–2.5 mm², or 2x 4 mm². The four NO contacts are rated for switching at 50/60 Hz with a rated insulation voltage of 690 V. At 110 V the contact current is 1 A; at 220 V it drops to 0.27 A, and at 500 V to 2 A — the non-linear derating reflects the arc extinction capability at higher voltages. Shock resistance is 10g / 5 ms and 5g / 10 ms, adequate for most industrial machinery but not for high-vibration mobile equipment without additional support.