What this 4-pole MCB does and where it fits
The Siemens SENTRON 5SL4403-7RC is a 4-pole miniature circuit breaker with a C tripping characteristic, rated 3 A at 415 V AC and a 10 kA breaking capacity per EN 60898. That C-curve means it handles moderate inrush — typical for motor starters, small transformers, or lighting groups — without nuisance tripping on start-up, while still clearing faults within the 10 kA limit. The 4-pole configuration (3 phases + neutral, though neutral is not switched per the spec) suits three-phase subfeeders in residential or light-commercial distribution boards.
Terminal capacity and wire sizes
Tightening torque range is 2.5 to 3 N·m.