What this 4-pole MCB does in a panel
Rated 4 A with a C-curve trip characteristic, it protects branch circuits against overload and short-circuit up to 3 kA per EN 60898 at 400 V AC, 50 Hz. Overvoltage category 3 and energy limiting class 3 place it in standard distribution-board duty — suitable for final subcircuits in residential or light commercial panels where the neutral conductor must be switched alongside the phases.
The 3P+N configuration with factory-fitted neutral switching means it drops into a 4-pole slot without external bridging — verify the busbar pitch matches your panel's 3-module layout before committing.
At 4 A, the thermal element protects a 0.9 kW resistive load at 230 V single-phase or roughly 2.8 kW three-phase at 400 V. If your panel's fault level is higher, step up to a 3VA molded-case frame. Energy limiting class 3 means it lets through enough energy to coordinate with downstream devices in a selective scheme — coordination curves are in the Siemens T55 manual.