The Siemens SIRIUS 3RH7131-1AN20 is a Size S00 contactor relay with a 31 E contact configuration — 3 normally open and 1 normally closed auxiliary contacts, all rated for PLC-level reliability at 17 V, 5 mA. The AC coil draws 27 VA pick-up and 5.4 VA holding, with a closing power factor of 0.8 and holding power factor of 0.27. Rated operational currents span 6 A at 24 V, 230 V, and 400 V, dropping to 1 A at 690 V and 0.3 A at 220 V.
The 45 mm width and 72 mm depth fit a standard S00 footprint — three units occupy roughly 135 mm of rail, leaving room for a 4-pole breaker alongside in a 400 mm wide enclosure. Screw-type terminals accept 2x 0.5 to 4 mm² solid or stranded, or 2x 0.5 to 2.5 mm² ferruled. The 8 mm strip length and spring-cage alternative aren't listed here — this is a screw clamp, so torque the terminal to the value on the nameplate, not feel.
The 18 kV surge voltage resistance means this relay withstands the switching transients common in motor control centers without external suppression on the coil — though adding an RC snubber across the coil terminals is still good practice for long wire runs. The DC-13 operating frequency of 1 000 1/h (roughly one operation every 3.6 seconds) suits high-cycle applications like conveyor indexing or packaging machine gates. Contact reliability at 17 V, 5 mA is explicitly rated for PLC input compatibility — the silver-alloy contacts are gold-flashed or treated to avoid oxidation at dry-circuit levels. This means you can wire this relay's NO contacts directly to a 24 VDC PLC input card without worrying about contact wetting current. Shock resistance of 15g for 5 ms sine pulse and 10g for 5 ms rectangular pulse covers most industrial vibration profiles — think crushers, presses, or overhead cranes. The storage temperature range of -25 to +70 °C and operating range of -10 to +55 °C are standard for indoor panel installation; derate if mounted near a heat source like a VFD or braking resistor.