What it is and what it does
The Siemens 3RH1344-1BF40-ZW97 is a SIRIUS contactor relay in size S00, carrying 4 normally-open and 4 normally-closed contacts with a DC 110 V coil and screw-type terminals. It's the switching element you'd wire into a control panel to multiply contact signals from a PLC output or a safety relay — the 4NO+4NC arrangement gives you enough isolated poles to drive multiple loads or feedback paths without adding an auxiliary contact block.
Coil and contact considerations
The DC 110 V coil is a common voltage in European control circuits, but it pulls a steady holding current — unlike an AC coil, there's no drop in holding power after pickup. That means the DC supply feeding it needs to be sized for continuous draw, and the PLC output or relay driving it must handle the inrush without voltage sag. The screw terminals accept standard ferrule or solid wire; strip length and torque follow the SIRIUS S00 terminal spec, which is consistent across the 3RH1 family.
Panel integration
Size S00 snaps onto a DIN rail in the standard enclosure footprint shared across the SIRIUS 3RH1 contactor relay range. The screw terminals are front-accessible, which keeps wiring tidy in a crowded panel. No special tooling needed beyond a screwdriver and a ferrule crimper for stranded wire.