SIRIUS 3RV1021-1HA15 — motor-protective circuit breaker, 8 A, Class 10
The Siemens 3RV1021-1HA15 is a SIRIUS motor-protective circuit breaker rated for 8 A continuous current with Trip Class 10, designed to protect 3 kW motors at 400 V AC. It snaps onto a 35 mm DIN rail per DIN EN 50022 and accepts screw-type terminals for both main and auxiliary circuits — solid conductors up to 2.5 mm² and stranded up to 6 mm². Phase failure detection is built in; ground fault detection is not. The IP20 front protection keeps live parts behind the panel door, standard for motor control centers.
Breaking capacity and coordination
This breaker delivers 100 kA breaking capacity at 240 V and 400 V AC, dropping to 42 kA at 500 V and 6 kA at 690 V AC. That 100 kA at 400 V means it can interrupt a bolted fault on a large transformer-fed line without upstream fuses — a real advantage in high-SCCR panel designs. The rated insulation voltage is 690 V, and surge voltage resistance is 6 000 V.
Mounting and integration
Mounts in any position via screw fixing or snap-on onto 35 mm DIN rail. The 45 mm width (3 TE) fits standard panel layout grids. Depth is 96 mm, height 97 mm — check clearance behind the door if using deep enclosures. Auxiliary switch option is transverse design and can be added as a product extension.