What it is and what it does
The Siemens 3RV1031-4EB15-ZX95 is a SIRIUS motor protection circuit breaker designed for motor protection, rated at 32 A continuous current with a CLASS 20 trip characteristic — meaning it allows a 20-second overload at 600% of the set current before tripping, which is the standard for standard-duty induction motors (pumps, fans, compressors) that don't need a faster trip curve. Breaking capacity hits 100 kA at 240 V AC, 50 kA at 400 V AC, 10 kA at 500 V AC, and 4 kA at 690 V AC — so at 400 V it clears faults up to 50 kA without cascading upstream, which is the typical SCCR requirement for a 400 V motor branch circuit in industrial panels. It detects phase failure (so a lost phase won't let the motor single-phase to destruction) but does not include ground-fault detection — that's handled separately by a GFCI or residual-current device downstream. Rated operational voltage is 690 V AC, and the AC-3 maximum switching frequency is 15 operations per hour — fine for a motor start/stop cycle on a conveyor or pump, not for a high-cycle application like a rapid-indexing servo.
Mounting and integration
Mounts via screw and snap-on onto a 35 mm DIN rail per DIN EN 50022, in any position — no derating needed for horizontal vs vertical orientation. Width is 55 mm, height 140 mm, depth 149 mm — a standard 3-module footprint on the rail, leaving room for adjacent contactors or overloads. Main circuit terminals are screw-type with box terminals, accepting solid conductors 2x (0.5…1.5 mm²) and 2x (0.75…2.5 mm²), or stranded 2x (0.75…25 mm²) and 1x (0.75…35 mm²) — covers most motor feeder wire sizes up to 35 mm². Auxiliary and control circuit terminals are also screw-type, and the breaker accepts an auxiliary switch (product extension auxiliary switch is available) — transverse design, so it mounts alongside the main body without extra depth. Clearance: 0 mm backwards and 0 mm at the side — meaning it can be butted directly against other devices on the rail without spacing, which saves panel width.
Environmental and approvals
Front protection class is IP20 — safe for finger contact in a closed panel; the body itself is not sealed for washdown (no IP65/67 rating here). Operating temperature range is -20 to +60 °C; storage and transport range is -50 to +80 °C — handles standard industrial ambient conditions. Shock resistance rated at 25 g for 11 ms — suitable for mounting on machinery that sees vibration, like a pump skid or conveyor drive. RoHS compliance date is July 1, 2006 — the part meets EU RoHS requirements. Power dissipation in hot operating state is 19 W — factor that into panel thermal calculations if the enclosure is sealed.