The Siemens 3RQ4038-1AF00 is a SIRIUS 3RQ4 coupling relay — an input coupler with an integrated relay in a narrow 6.2 mm housing. It switches one change-over contact rated for a thermal current of 6 A, with a 230 V AC/DC coil. The screw-terminal design suits permanent panel wiring where you want a compact, DIN-rail-mounted interface between a control signal and a load circuit. The 6.2 mm width is the key space-saving feature here — it packs a single relay function into roughly half the width of a standard 12 mm interface relay, which matters when you're populating a crowded DIN-rail enclosure and every millimeter of rail counts.
RoHS compliance is confirmed from September 2024 onward. Export control is straightforward: AL N / ECCN EAR99, no licensing barrier.
Integration notes
The 6.2 mm width means you can fit multiple units side-by-side in a terminal-block-style layout. Screw terminals accept typical control wiring — strip length and ferrule sizing follow standard practice for interface relays in this class. The 230 V AC/DC coil covers both common control voltages without needing a separate rectifier or AC/DC selection jumper.