What this SIRIUS breaker does on the line
The Siemens 3RV1011-1KA10-ZW98 is a SIRIUS motor protection circuit breaker designed to sit between the contactor and the motor on a 35 mm DIN rail. It combines short-circuit and overload protection in one 45 mm wide package, with a Class 10 trip curve that matches standard induction motor start profiles — the breaker holds through a 10-second start and trips fast on a locked rotor. Phase failure detection is built in, so a single-phased motor drops off before the winding temperature climbs.
Breaking capacity — where the SCCR matters
At 240 V the 3RV1011-1KA10-ZW98 interrupts 100 kA, which covers most North American panel SCCR targets without an upstream fuse. At 400 V it holds 13 kA, enough for European industrial grids with typical transformer impedances. The gL/gG fuse coordination limits are 80 A at 240 V and 400 V, dropping to 50 A at 500 V and 690 V — that tells you the maximum backup fuse that still lets the breaker clear a fault within its let-through curve.
Mounting and panel fit
The breaker snaps onto 35 mm DIN rail per DIN EN 60715, or screws directly to a backplate. At 45 mm wide and 75 mm deep, it occupies one standard modular slot — no extra side clearance needed beyond the 9 mm at the side. Mounting position is any orientation, which simplifies layout in a tight enclosure. Terminals accept 2x 0.5 to 2.5 mm² solid or stranded, and the main contact screws are M3.