4 NO auxiliary switching in a size S00 frame
The 3RH2140-2BF40 is a SIRIUS auxiliary contactor with four normally-open instantaneous contacts, sized in the S00 frame. It is designed for signal-level switching in control circuits, not motor power — the 4 NO configuration gives you four independent signal paths that close when the coil is energized. Closing power is 4 W, holding power also 4 W, meaning the coil driver must deliver a continuous 4 W load without thermal derating. Switching capacity varies sharply with DC voltage: at 24 V it handles 10 A, at 110 V it drops to 3 A, and at 600 V it is rated only 0.26 A. For AC loads at 230 V it switches 10 A, at 400 V it switches 3 A. This voltage-dependent derating is the primary selection constraint — the same contact pair cannot carry its full 24 V rating at a higher DC bus voltage.
DIN rail fit and panel clearances
This means it fits in tight sub-panels where the rail is not perfectly vertical. Physical envelope is 70 mm high, 45 mm wide, 73 mm deep. At 45 mm wide, four units fit in a standard 180 mm DIN-rail segment — plan your gland-plate layout accordingly. Pollution degree 3 means it is rated for conductive pollution environments typical of industrial control panels — no conformal coating required for normal factory-floor atmospheres.
Lifecycle, compliance, and sourcing posture
Mechanical life is rated 30,000,000 operating cycles typical — this is the wear-out limit for the contact mechanism, not the electrical endurance under load. At the maximum AC switching rate of 10,000 operations per hour, the mechanical life translates to roughly 3,000 hours of continuous cycling, or about 125 days of 24/7 operation.