The Siemens 3RQ4038-1AE01 is a SIRIUS 3RQ4 coupling relay in the narrow 6.2 mm housing, designed to isolate and switch control signals in industrial automation panels. It accepts a 115 V AC/DC control voltage and routes it through one change-over contact rated for 6 A thermal current. The hard gold-plated contacts handle low-level switching reliably, making it suitable for PLC output isolation or signal conditioning in mixed-voltage cabinets.
The 6 A thermal current (Ith) is the continuous carry rating through the closed contact — it governs the maximum resistive load the relay can pass without derating. For motor or inductive loads, you'll need to apply the appropriate AC/DC utilization category derating; the 6 A figure is the ceiling for resistive switching. The 115 V AC/DC coil gives you flexibility: it runs on either supply type without a separate rectifier, simplifying panel wiring on mixed-voltage lines. At 6.2 mm wide, this relay occupies minimal DIN-rail space — roughly half the width of a standard 12.5 mm interface relay. In a dense control cabinet, that translates to more I/O channels per meter of rail, or room for additional surge suppressors and ferrules.
This relay has been RoHS-compliant since 26 September 2024, meeting the substance restrictions under EU Directive 2011/65/EU. No UL or CSA listing appears in the available spec record; verify local code acceptance with your Siemens representative if your jurisdiction requires third-party certification.