The Siemens SIRIUS 3RH1131-1JB40 is a coupling relay for switching auxiliary circuits — a 24 V DC coil drives three normally-open (3 NO) instantaneous contacts rated 10 A at 24 V. The Size S00 footprint (45 mm wide, 57.5 mm tall, 72 mm deep) fits the standard SIRIUS contactor relay family, mounting by screw or snap-on onto DIN rail. Coil hold power is 2.3 W DC, with an integrated diode surge suppressor across the coil — no external flyback diode needed for DC switching.
The 10 A at 24 V rating defines the maximum continuous thermal current for the auxiliary contacts at the coil voltage — this is the figure to check against the load current of pilot lights, PLC inputs, or small contactor coils the relay will switch. The 3 NO instantaneous contacts switch without delay; there are no delayed, lagging, or make-before-break contacts on this variant. The leading contact count is zero, meaning all three contacts close simultaneously within the contactor's mechanical tolerance. Terminals accept solid conductors: 2x 0.5…1.5 mm², 2x 0.75…2.5 mm², or 2x 4 mm² — sufficient for standard control wiring in panels. The front protection class is IP20, which is typical for enclosed panel-mount devices; no IP rating for the housing sides is stated, so the relay relies on the enclosure for environmental protection.
Mount the 3RH1131-1JB40 on DIN rail using the integrated snap-on feature, or secure it with screws through the mounting slots. The Size S00 profile (45 mm wide) matches the footprint of SIRIUS contactors like the 3RT201 or 3RT202 series, so the coupling relay can be ganged directly alongside or stacked with a contactor on the same DIN rail without losing alignment. Shock resistance is 10g for 5 ms and 5g for 10 ms — sufficient for most industrial panel applications, but not rated for extreme vibration environments such as direct engine mounting without additional damping.
RoHS compliance date is stated as 1 July 2006, confirming the relay meets the original RoHS directive.