The Siemens 3RQ4038-2AE00 is a SIRIUS 3RQ4 coupling relay in the narrow 6.2 mm housing. It takes a 115 V AC/DC control signal on the input side and switches a single changeover contact rated for 6 A thermal current. This is an input coupler with an integrated relay, meaning the input circuit and the contact circuit are galvanically isolated. The 115 V AC/DC coil covers both AC and DC control voltages on the same winding, so you don't need to spec a separate coil variant for mixed-voltage panels.
The narrow profile packs more channels per linear inch of rail — useful when the gland plate is full or the enclosure depth is tight. The push-in terminals face forward, so wiring doesn't add width to the row. Packaged singly, dimensions 95 x 93 x 65 mm. The 6 A thermal current is the continuous carry rating at ambient; if you're grouping several relays in a confined enclosure, factor in the heat rise from the coil draw and contact I²R losses.
RoHS compliant since 26 September 2024.