The Siemens 5SL6340-7YA is a SENTRON miniature circuit breaker — 3-pole, C-curve, rated 40 A at 400 V AC, with a 6 kA breaking capacity per EN 60898. It protects branch circuits in residential and infrastructure distribution boards against overload and short-circuit. At 45 °C ambient the continuous rating derates to 36.8 A, so a panel running warm needs a size-up if the load is near 40 A.
Installation depth behind the panel is 70 mm. The housing is sealable (tamper-evident seal available), halogen-free and silicon-free, rated IP20 with the distribution board cover fitted. Any mounting position is allowed. Pollution degree 2, overvoltage category III — typical for fixed-installation switchgear in dry, non-conductive environments.
This is a current-production part — no phase-out or last-time-buy notice on record. The SENTRON 5SL series is Siemens' standard residential and light-commercial MCB line, widely specified across Europe and Asia. Same part, different passport — genuine is genuine.