What it is and what it does
The Siemens SIRIUS 3RV1021-1GA10-ZW98 is a motor protection circuit breaker rated for 6.3 A continuous current and 2.2 kW motor power at 400 V AC. It's a three-pole device with screw-type terminals for both main and auxiliary circuits, designed to protect motors against overload, short circuit, and phase failure. The Class 10 trip characteristic means it disconnects within 10 seconds at 7.2× the thermal setting — standard for protecting standard induction motors during locked-rotor starts. Phase failure detection is built in, so a lost phase on the line side trips the breaker rather than letting the motor single-phase and burn.
Breaking capacity and where it matters
This breaker delivers 100 kA breaking capacity at 240 V, 400 V, and 500 V AC, dropping to 6 kA at 690 V AC. The 100 kA figure covers most industrial distribution panels fed from a transformer of several hundred kVA — it interrupts a bolted fault without the upstream fuse or breaker needing to clear. At 690 V the 6 kA rating still handles the majority of motor-starting faults in 690 V systems.
Mounting and panel fit
Mounts via screw or snap-on onto 35 mm DIN rail per EN 50022. Width is 45 mm. Any mounting position allowed. Terminals accept 1 to 6 mm² solid or stranded wire (two conductors per clamp), or AWG 14 to 10. The screw terminals are the same type for main and auxiliary circuits, so the wireman uses one tool. IP20 on the front — protected against finger contact, not for washdown areas.
Lifecycle and sourcing
The -ZW98 suffix indicates a special version (customer-specific variant). Verify the exact configuration against your BOM — the base electrical ratings (6.3 A, Class 10, 100 kA) are standard, but the ZW code may carry a factory-set thermal adjustment or accessory package that differs from the standard 3RV1021-1GA10.